diff --git a/README.md b/README.md
index 7baa1bb6df..2029c2b9cc 100644
--- a/README.md
+++ b/README.md
@@ -2,6 +2,8 @@ Firebug
 =======
 *Web Development Evolved* [getfirebug.com](https://getfirebug.com)
 
+**On November 14, with the launch of Firefox Quantum (AKA 57), support for old school extensions will stop in Firefox. That means Firebug will no longer work for many developers. However, the work continues in the great Firefox devtools. You can try Firefox devtools by updating your [release browser](https://www.mozilla.org/en-US/firefox/new/?utm_source=github&utm_campaign=switch) or [downloading Developer Edition](https://www.mozilla.org/en-US/firefox/developer/?utm_source=github&utm_campaign=switch). Read more [here](https://hacks.mozilla.org/2017/10/saying-goodbye-to-firebug/)**
+
 [Download](https://addons.mozilla.org/en-US/firefox/addon/firebug/)
 
 License
diff --git a/extension/bootstrap.js b/extension/bootstrap.js
index 17784cb51e..6ee6a33a3f 100644
--- a/extension/bootstrap.js
+++ b/extension/bootstrap.js
@@ -74,8 +74,9 @@ function startup(params, reason)
     Services.obs.addObserver(windowWatcher, "chrome-document-global-created", false);
 
     // GCLI commands
-    Cu.import("resource://firebug/gcli.js");
-    FirebugGCLICommands.startup();
+    // Not supported anymore
+    //Cu.import("resource://firebug/gcli.js");
+    //FirebugGCLICommands.startup();
 }
 
 function shutdown(params, reason)
diff --git a/extension/content/firebug/branch.properties b/extension/content/firebug/branch.properties
index c9f12cf85b..c7381baa50 100644
--- a/extension/content/firebug/branch.properties
+++ b/extension/content/firebug/branch.properties
@@ -1,5 +1,5 @@
 # DO NOT MERGE INTO TRUNK
-RELEASE=.11
+RELEASE=.19
 VERSION=2.0
 TRUNK=
 # To allow build.xml to drop the xpi directly into the svn working copy for getfirebug.com
diff --git a/extension/content/firebug/bti/inProcess/browser.js b/extension/content/firebug/bti/inProcess/browser.js
index 9fb8a937e3..2de7fc527b 100644
--- a/extension/content/firebug/bti/inProcess/browser.js
+++ b/extension/content/firebug/bti/inProcess/browser.js
@@ -453,7 +453,7 @@ Browser.prototype.removeListener = function(listener)
         FBTrace.sysout("BTI.Browser.removeListener; ERROR Unknown listener " +
             (listener.dispatchName ? listener.dispatchName : ""));
 
-    // xxxHonza: should it be alwasy called or only if isConnected() == true?
+    // xxxHonza: should it be always called or only if isConnected() == true?
     //if (this.isConnected())
         Events.dispatch2([listener], "onDisconnect", [this]);
 };
diff --git a/extension/content/firebug/chrome/reps.js b/extension/content/firebug/chrome/reps.js
index a6bad2da43..2f1518afaf 100644
--- a/extension/content/firebug/chrome/reps.js
+++ b/extension/content/firebug/chrome/reps.js
@@ -2349,7 +2349,7 @@ FirebugReps.XPathResult = domplate(FirebugReps.Arr,
         // xxxHonza: fix for test console/api/log-xpathresult
         // FirebugReps.Arr.hasSpecialProperties iterates object properties
         // (using Object.getOwnPropertyNames), but misses 'constructor' if the property
-        // is not explicitely accessed before. Any explanation for such behavior?
+        // is not explicitly accessed before. Any explanation for such behavior?
         // (btw. it was actually accessed, but order of 'supportsObject' calls changed when
         // 'Exception' rep moved into its own module, see issue: 6606)
         var ctor = array && array.constructor;
diff --git a/extension/content/firebug/chrome/tabWatcher.js b/extension/content/firebug/chrome/tabWatcher.js
index 6a6cc4be6a..9b87f35ff4 100644
--- a/extension/content/firebug/chrome/tabWatcher.js
+++ b/extension/content/firebug/chrome/tabWatcher.js
@@ -954,7 +954,7 @@ var TabProgressListener = Obj.extend(Http.BaseProgressListener,
             // switching to about:blank tab, see issue 4040
             //
             // 2) But we also want to skip "about:blank" in case a new tab is opened
-            // (new tab is about:blank at the beggining), no context exists and Firebug
+            // (new tab is about:blank at the beginning), no context exists and Firebug
             // is suspended for all contexts, see issue5916
             // There is a workaround for this case in {@TabWatchListener.showContext]
             //
diff --git a/extension/content/firebug/chrome/window.js b/extension/content/firebug/chrome/window.js
index e3b4ab6f41..96831292d2 100644
--- a/extension/content/firebug/chrome/window.js
+++ b/extension/content/firebug/chrome/window.js
@@ -17,7 +17,7 @@ var wm = Cc["@mozilla.org/appshell/window-mediator;1"].getService(Ci.nsIWindowMe
 
 var Win = {};
 
-var window = {};     // these declarations exist to cause errors if we accidently
+var window = {};     // these declarations exist to cause errors if we accidentally
 var document = {};   // reference these globals
 
 // ********************************************************************************************* //
diff --git a/extension/content/firebug/console/autoCompleter.js b/extension/content/firebug/console/autoCompleter.js
index 6b61ea5f1c..def277fc84 100644
--- a/extension/content/firebug/console/autoCompleter.js
+++ b/extension/content/firebug/console/autoCompleter.js
@@ -1000,7 +1000,7 @@ JSAutoCompleter.transformScopeOperator = function(expr, fname)
     var search = 0;
     for (;;)
     {
-        // Find the next occurrance of .%.
+        // Find the next occurrence of .%.
         var end = sexpr.indexOf(".%", search);
         if (end === -1)
             break;
diff --git a/extension/content/firebug/console/closureInspector.js b/extension/content/firebug/console/closureInspector.js
index 3226f6c9b2..590efcd10d 100644
--- a/extension/content/firebug/console/closureInspector.js
+++ b/extension/content/firebug/console/closureInspector.js
@@ -159,7 +159,7 @@ var ClosureInspector =
         var objGlobal = Cu.getGlobalForObject(obj);
 
         // Do a security check. This is automatic in Fx33+, but do it manually
-        // (with the same error message) for compatiblity with older versions.
+        // (with the same error message) for compatibility with older versions.
         if (win !== objGlobal && !(win.document && objGlobal.document &&
             win.document.nodePrincipal.subsumes(objGlobal.document.nodePrincipal)))
         {
diff --git a/extension/content/firebug/console/commandEditor.js b/extension/content/firebug/console/commandEditor.js
index 8ab0e18274..95c3bb006a 100644
--- a/extension/content/firebug/console/commandEditor.js
+++ b/extension/content/firebug/console/commandEditor.js
@@ -11,13 +11,14 @@ define([
     "firebug/lib/options",
     "firebug/lib/promise",
     "firebug/lib/string",
+    "firebug/lib/devtools",
     "firebug/chrome/module",
     "firebug/chrome/menu",
     "firebug/console/autoCompleter",
     "firebug/console/commandLine",
     "firebug/editor/sourceEditor",
 ],
-function(Firebug, FBTrace, Obj, Events, Dom, Locale, Css, Options, Promise, Str, Module, Menu,
+function(Firebug, FBTrace, Obj, Events, Dom, Locale, Css, Options, Promise, Str, DevTools, Module, Menu,
     AutoCompleter, CommandLine, SourceEditor) {
 
 "use strict";
@@ -352,49 +353,32 @@ var CommandEditor = Obj.extend(Module,
             return;
 
         var worker = getPrettyPrintWorker();
+        if (!worker) {
+          return;
+        }
+
         var id = "firebug-" + Obj.getUniqueId();
         var deferred = Promise.defer();
 
-        var onReply = ({data}) =>
-        {
-            if (data.id !== id)
-                return;
-
-            worker.removeEventListener("message", onReply, false);
-
-            if (data.error)
-            {
-                TraceError.sysout("commandEditor.prettyPrint; ERROR " + data.error, data);
-
-                // Remove stack trace info from the error message (separated by a newline,
-                // see pretty-print-worker.js)
-                var message = Str.safeToString(data.error);
-                var index = message.indexOf("\n");
-                message = message.substr(0, index);
-
-                // Log only an error message into the Console panel.
-                Firebug.Console.logFormatted([message], context, "error", true);
-
-                deferred.reject(data.error);
-            }
-            else
-            {
-                this.setText(data.code);
-
-                deferred.resolve(data.code);
-            }
-        };
-
-        worker.addEventListener("message", onReply, false);
-
-        worker.postMessage({
-            id: id,
-            url: "(command-editor)",
-            indent: Options.get("replaceTabs"),
-            source: this.getText()
+        return worker.performTask("pretty-print", {
+          url: "(command-editor)",
+          indent: Options.get("replaceTabs"),
+          source: this.getText()
+        }).then(data => {
+          this.setText(data.code);
+        }).then(null, error => {
+          TraceError.sysout("commandEditor.prettyPrint; ERROR " + error, error);
+
+          // Remove stack trace info from the error message (separated by a newline,
+          // see pretty-print-worker.js)
+          var message = Str.safeToString(error);
+          var index = message.indexOf("\n");
+          if (index != -1)
+            message = message.substr(0, index);
+
+          // Log only an error message into the Console panel.
+          Firebug.Console.logFormatted([message], context, "error", true);
         });
-
-        return deferred.promise;
     }
 });
 
@@ -522,14 +506,15 @@ function getPrettyPrintWorker()
 {
     if (!prettyPrintWorker)
     {
-        prettyPrintWorker = new ChromeWorker(
-            "resource://gre/modules/devtools/server/actors/pretty-print-worker.js");
+        if (!DevTools.DevToolsWorker)
+          return null;
 
-        prettyPrintWorker.addEventListener("error", ({message, fileName, lineNo}) =>
-        {
-            TraceError.sysout("commandEditor.getPrettyPrintWorker; ERROR " + message +
-                " " + fileName + ":" + lineNo);
-        }, false);
+        prettyPrintWorker = new DevTools.DevToolsWorker(
+            DevTools.prettyPrintWorkerUrl, {
+                name: "pretty-print",
+                verbose: DevTools.DevToolsUtils.dumpn.wantLogging
+            }
+        );
     }
 
     return prettyPrintWorker;
diff --git a/extension/content/firebug/console/commandLineExposed.js b/extension/content/firebug/console/commandLineExposed.js
index dbaa0e7911..4b8ebe5468 100644
--- a/extension/content/firebug/console/commandLineExposed.js
+++ b/extension/content/firebug/console/commandLineExposed.js
@@ -237,8 +237,8 @@ function evaluateInGlobal(context, win, expr, origExpr, onSuccess, onError, opti
 {
     var dbgGlobal = DebuggerLib.getInactiveDebuggeeGlobal(context, win);
     var evalMethod = options.noCmdLineAPI ?
-                     dbgGlobal.evalInGlobal :
-                     dbgGlobal.evalInGlobalWithBindings;
+                     (dbgGlobal.executeInGlobal || dbgGlobal.evalInGlobal) :
+                     (dbgGlobal.executeInGlobalWithBindings || dbgGlobal.evalInGlobalWithBindings);
 
     var args = [dbgGlobal, evalMethod, dbgGlobal];
     args.push.apply(args, arguments);
@@ -528,8 +528,11 @@ function executeInWindowContext(win, func, args, dbgGlobal)
     var code = "(function() { callback(); })";
     var bindings = Object.create(null);
     bindings.callback = dbgGlobal.makeDebuggeeValue(listener);
-    var listenerInWindow = dbgGlobal.evalInGlobalWithBindings(code, bindings)
-        .return.unsafeDereference();
+    var listenerInWindow = (
+            dbgGlobal.executeInGlobalWithBindings ?
+            dbgGlobal.executeInGlobalWithBindings(code, bindings) :
+            dbgGlobal.evalInGlobalWithBindings(code, bindings)
+        ).return.unsafeDereference();
 
     win.document.addEventListener("firebugCommandLine", listenerInWindow);
 
diff --git a/extension/content/firebug/console/commands/commandLineInclude.js b/extension/content/firebug/console/commands/commandLineInclude.js
index 88091c3e4b..3f3683e454 100644
--- a/extension/content/firebug/console/commands/commandLineInclude.js
+++ b/extension/content/firebug/console/commands/commandLineInclude.js
@@ -15,13 +15,14 @@ define([
     "firebug/lib/system",
     "firebug/lib/xpcom",
     "firebug/lib/object",
+    "firebug/lib/devtools",
     "firebug/chrome/tableRep",
     "firebug/console/console",
     "firebug/editor/editor",
     "firebug/editor/inlineEditor",
 ],
 function(Module, Rep, FirebugReps, Domplate, Locale, Dom, Win, Css, Str, Options, Menu, System,
-    Xpcom, Obj, TableRep, Console, Editor, InlineEditor) {
+    Xpcom, Obj, DevTools, TableRep, Console, Editor, InlineEditor) {
 
 // ********************************************************************************************* //
 // Constants
@@ -37,19 +38,7 @@ var Trace = FBTrace.to("DBG_COMMANDLINE");
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
-var ScratchpadManager;
-
-try
-{
-    var scope = {};
-    Cu.import("resource:///modules/devtools/scratchpad-manager.jsm", scope);
-    ScratchpadManager = scope.ScratchpadManager;
-}
-catch(ex)
-{
-    // Scratchpad does not exists (when using Seamonkey ...)
-}
-
+var ScratchpadManager = DevTools.ScratchpadManager;
 var storageScope = {}, StorageService;
 Cu.import("resource://firebug/storageService.js", storageScope);
 StorageService = storageScope.StorageService;
@@ -304,7 +293,7 @@ var CommandLineIncludeRep = domplate(TableRep,
             }
         ];
 
-        if (ScratchpadManager)
+        if (typeof ScratchpadManager.openScratchpad == "function")
         {
             items.push({
                 label: "commandline.label.OpenInScratchpad",
diff --git a/extension/content/firebug/console/console.js b/extension/content/firebug/console/console.js
index 282a2fa5f3..6947ede84c 100644
--- a/extension/content/firebug/console/console.js
+++ b/extension/content/firebug/console/console.js
@@ -10,6 +10,7 @@ define([
     "firebug/lib/wrapper",
     "firebug/lib/xml",
     "firebug/lib/options",
+    "firebug/lib/devtools",
     "firebug/chrome/window",
     "firebug/chrome/firefox",
     "firebug/chrome/panelNotification",
@@ -21,7 +22,7 @@ define([
     "firebug/dom/domBaseTree",
     "firebug/remoting/debuggerClient",
 ],
-function(Firebug, FBTrace, Obj, Events, Locale, Search, Wrapper, Xml, Options, Win, Firefox,
+function(Firebug, FBTrace, Obj, Events, Locale, Search, Wrapper, Xml, Options, DevTools, Win, Firefox,
     PanelNotification, ActivableModule, ConsoleBase, SourceLink, StackFrame, StackTrace,
     DomBaseTree, DebuggerClient) {
 
@@ -30,9 +31,9 @@ function(Firebug, FBTrace, Obj, Events, Locale, Search, Wrapper, Xml, Options, W
 // ********************************************************************************************* //
 // Constants
 
-var Cu = Components.utils;
-var scope = Cu.import("resource://gre/modules/devtools/Loader.jsm", {});
-var {ConsoleAPIListener} = scope.devtools.require("devtools/toolkit/webconsole/utils");
+var {ConsoleAPIListener} = DevTools.safeRequire(DevTools.devtools,
+  "devtools/shared/webconsole/utils",
+  "devtools/toolkit/webconsole/utils");
 
 var defaultReturnValue = Object.preventExtensions(Object.create(null));
 
diff --git a/extension/content/firebug/console/errorStackTraceObserver.js b/extension/content/firebug/console/errorStackTraceObserver.js
index c1ef6b0532..f42445d22d 100644
--- a/extension/content/firebug/console/errorStackTraceObserver.js
+++ b/extension/content/firebug/console/errorStackTraceObserver.js
@@ -154,9 +154,17 @@ var ErrorStackTraceObserver = Obj.extend(Module,
             if (!sourceFile)
                 sourceFile = {href: script.url};
 
-            var line = script.getOffsetLine(state.offsets[i]);
-            var args = state.argCopies[i];
+            var line;
+
+            // getOffsetLocation has been introduced in Firefox 44 (Fx44)
+            // https://bugzilla.mozilla.org/show_bug.cgi?id=863089
+            // https://github.com/firebug/firebug/issues/7961
+            if (typeof script.getOffsetLocation == "function")
+                line = script.getOffsetLocation(state.offsets[i]).lineNumber;
+            else
+                line = script.getOffsetLine(state.offsets[i]);
 
+            var args = state.argCopies[i];
             var stackFrame = new StackFrame(sourceFile, line, state.frameNames[i],
                 args, null, 0, context);
             trace.frames.push(stackFrame);
diff --git a/extension/content/firebug/cookies/cookieObserver.js b/extension/content/firebug/cookies/cookieObserver.js
index 9e0f0a92d8..f76442c947 100644
--- a/extension/content/firebug/cookies/cookieObserver.js
+++ b/extension/content/firebug/cookies/cookieObserver.js
@@ -432,7 +432,7 @@ var CookieObserver = Obj.extend(BaseObserver,
 
     logEvent: function(eventObject, context, className)
     {
-        // xxxHonza: if the cookie is changed befor initContext, the log in
+        // xxxHonza: if the cookie is changed before initContext, the log in
         // console is lost.
         Firebug.Console.log(eventObject, context, className, null, true);
     }
diff --git a/extension/content/firebug/cookies/cookiePanel.js b/extension/content/firebug/cookies/cookiePanel.js
index 3bbe9088cc..5f55ca66bc 100644
--- a/extension/content/firebug/cookies/cookiePanel.js
+++ b/extension/content/firebug/cookies/cookiePanel.js
@@ -499,7 +499,7 @@ CookiePanel.prototype = Obj.extend(ActivablePanel,
 // Cookie Breakpoints
 
 /**
- * @class Represents an {@link Debugger} listener. This listener is reponsible for
+ * @class Represents an {@link Debugger} listener. This listener is responsible for
  * providing a list of cookie breakpoints for the Breakpoints side panel.
  */
 CookieModule.DebuggerListener =
diff --git a/extension/content/firebug/cookies/cookieReps.js b/extension/content/firebug/cookies/cookieReps.js
index 38e4d9cb78..4ab8539efe 100644
--- a/extension/content/firebug/cookies/cookieReps.js
+++ b/extension/content/firebug/cookies/cookieReps.js
@@ -215,7 +215,7 @@ CookieReps.CookieRow = domplate(CookieReps.Rep,
             return "";
 
         // The first character is space so, if the table is sorted according
-        // to this column, all "Session" cookies are displayed at the begining.
+        // to this column, all "Session" cookies are displayed at the beginning.
         if (CookieUtils.isSessionCookie(cookie.cookie))
             return " " + Locale.$STR("cookies.Session");
 
diff --git a/extension/content/firebug/css/computedPanel.js b/extension/content/firebug/css/computedPanel.js
index c4d64eb904..5568976bd7 100644
--- a/extension/content/firebug/css/computedPanel.js
+++ b/extension/content/firebug/css/computedPanel.js
@@ -14,6 +14,7 @@ define([
     "firebug/lib/string",
     "firebug/lib/url",
     "firebug/lib/xml",
+    "firebug/lib/devtools",
     "firebug/chrome/menu",
     "firebug/chrome/panel",
     "firebug/css/cssModule",
@@ -22,7 +23,7 @@ define([
     "firebug/debugger/script/sourceLink",
 ],
 function(Firebug, Arr, Css, Dom, Domplate, Events, Locale, Obj, Options, Persist, Str, Url, Xml,
-    Menu, Panel, CSSModule, CSSReps, LoadHandler, SourceLink) {
+    DevTools, Menu, Panel, CSSModule, CSSReps, LoadHandler, SourceLink) {
 
 "use strict";
 
@@ -42,9 +43,10 @@ try
 {
     // Firefox 24
     // waiting for: https://bugzilla.mozilla.org/show_bug.cgi?id=867595
-    var scope = {}
-    Cu.import("resource://gre/modules/devtools/Loader.jsm", scope);
-    var {CssLogic} = scope.devtools.require("devtools/styleinspector/css-logic");
+    var {CssLogic} = DevTools.safeRequire(DevTools.devtools,
+      "devtools/shared/inspector/css-logic",
+      "devtools/shared/styleinspector/css-logic",
+      "devtools/styleinspector/css-logic");
 }
 catch (e)
 {
diff --git a/extension/content/firebug/debugger/actors/breakpointActor.js b/extension/content/firebug/debugger/actors/breakpointActor.js
index 07af36dc5f..fb850842cd 100644
--- a/extension/content/firebug/debugger/actors/breakpointActor.js
+++ b/extension/content/firebug/debugger/actors/breakpointActor.js
@@ -3,10 +3,11 @@
 define([
     "firebug/lib/object",
     "firebug/lib/trace",
+    "firebug/lib/devtools",
     "firebug/debugger/debuggerLib",
     "firebug/debugger/breakpoints/breakpointStore",
 ],
-function(Obj, FBTrace, DebuggerLib, BreakpointStore) {
+function(Obj, FBTrace, DevTools, DebuggerLib, BreakpointStore) {
 
 "use strict";
 
@@ -21,7 +22,7 @@ function(Obj, FBTrace, DebuggerLib, BreakpointStore) {
 
 var Cu = Components.utils;
 
-Cu["import"]("resource://gre/modules/devtools/dbg-server.jsm");
+var DebuggerServer = DevTools.DebuggerServer;
 
 // xxxHonza: Firefox 32 changes the location of BreakpointActor object,
 // but implements support for server side breakpoint condition evaluation
diff --git a/extension/content/firebug/debugger/actors/elementActor.js b/extension/content/firebug/debugger/actors/elementActor.js
index 4a97780a79..6e929f87d2 100644
--- a/extension/content/firebug/debugger/actors/elementActor.js
+++ b/extension/content/firebug/debugger/actors/elementActor.js
@@ -3,8 +3,9 @@
 define([
     "firebug/lib/object",
     "firebug/lib/trace",
+    "firebug/lib/devtools",
 ],
-function(Obj, FBTrace) {
+function(Obj, FBTrace, DevTools) {
 
 // ********************************************************************************************* //
 // Constants
@@ -13,7 +14,7 @@ var Cc = Components.classes;
 var Ci = Components.interfaces;
 var Cu = Components.utils;
 
-Cu["import"]("resource://gre/modules/devtools/dbg-server.jsm");
+var DebuggerServer = DevTools.DebuggerServer;
 
 // ********************************************************************************************* //
 // Implementation
diff --git a/extension/content/firebug/debugger/actors/objectActor.js b/extension/content/firebug/debugger/actors/objectActor.js
index 13639cd8b4..b2f5970ec7 100644
--- a/extension/content/firebug/debugger/actors/objectActor.js
+++ b/extension/content/firebug/debugger/actors/objectActor.js
@@ -4,8 +4,9 @@ define([
     "firebug/lib/object",
     "firebug/lib/trace",
     "firebug/lib/options",
+    "firebug/lib/devtools",
 ],
-function(Obj, FBTrace, Options) {
+function(Obj, FBTrace, Options, DevTools) {
 
 // ********************************************************************************************* //
 // Constants
@@ -14,8 +15,7 @@ var Cc = Components.classes;
 var Ci = Components.interfaces;
 var Cu = Components.utils;
 
-Cu["import"]("resource://gre/modules/devtools/dbg-server.jsm");
-
+var DebuggerServer = DevTools.DebuggerServer;
 var ObjectActor = DebuggerServer.ObjectActor;
 var propMax = Options.get("ObjectShortIteratorMax");
 
diff --git a/extension/content/firebug/debugger/actors/threadActor.js b/extension/content/firebug/debugger/actors/threadActor.js
index d2593e03e3..8d42389080 100644
--- a/extension/content/firebug/debugger/actors/threadActor.js
+++ b/extension/content/firebug/debugger/actors/threadActor.js
@@ -4,9 +4,10 @@ define([
     "firebug/lib/object",
     "firebug/lib/trace",
     "firebug/lib/options",
+    "firebug/lib/devtools",
     "firebug/debugger/actors/elementActor",
 ],
-function(Obj, FBTrace, Options, ElementActor) {
+function(Obj, FBTrace, Options, DevTools, ElementActor) {
 
 // ********************************************************************************************* //
 // Constants
@@ -15,8 +16,7 @@ var Cc = Components.classes;
 var Ci = Components.interfaces;
 var Cu = Components.utils;
 
-Cu["import"]("resource://gre/modules/devtools/dbg-server.jsm");
-
+var DebuggerServer = DevTools.DebuggerServer;
 var ThreadActor = DebuggerServer.ThreadActor;
 
 // ********************************************************************************************* //
diff --git a/extension/content/firebug/debugger/commands.js b/extension/content/firebug/debugger/commands.js
index d0b135883d..00258baa13 100644
--- a/extension/content/firebug/debugger/commands.js
+++ b/extension/content/firebug/debugger/commands.js
@@ -7,12 +7,13 @@ define([
     "firebug/lib/trace",
     "firebug/lib/object",
     "firebug/lib/options",
+    "firebug/lib/devtools",
     "firebug/chrome/module",
     "firebug/debugger/rdp",
     "firebug/debugger/debuggerLib",
     "firebug/debugger/breakpoints/breakpointStore"
 ],
-function(Firebug, FBTrace, Obj, Options, Module, RDP, DebuggerLib, BreakpointStore) {
+function(Firebug, FBTrace, Obj, Options, DevTools, Module, RDP, DebuggerLib, BreakpointStore) {
 
 "use strict";
 
@@ -23,7 +24,7 @@ var Cc = Components.classes;
 var Ci = Components.interfaces;
 var Cu = Components.utils;
 
-Cu["import"]("resource://gre/modules/devtools/dbg-server.jsm");
+var DebuggerServer = DevTools.DebuggerServer;
 
 var Trace = FBTrace.to("DBG_DEBUGGER_COMMANDS");
 var TraceError = FBTrace.toError();
diff --git a/extension/content/firebug/debugger/debuggerLib.js b/extension/content/firebug/debugger/debuggerLib.js
index 4360ed9b36..486e9af217 100644
--- a/extension/content/firebug/debugger/debuggerLib.js
+++ b/extension/content/firebug/debugger/debuggerLib.js
@@ -43,6 +43,10 @@ DebuggerLib.unwrapDebuggeeValue = function(obj)
     if (typeof obj !== "object" || obj === null)
         return obj;
 
+    if (typeof obj.unsafeDereference != "function") {
+      return;
+    }
+
     return Wrapper.unwrapObject(obj.unsafeDereference());
 };
 
@@ -147,6 +151,17 @@ DebuggerLib.getObject = function(context, actorId)
         if (!actor && threadActor._pausePool)
             actor = threadActor._pausePool.get(actorId);
 
+        // Check also the youngest frame that contains objects
+        // living in the scope.
+        // We could also iterate all frames through: threadActor.framePool,
+        // but it could have an impact on performance since this method
+        // is called quite often. It would have to be tested carefully.
+        if (!actor && threadActor.youngestFrame &&
+            threadActor.youngestFrame.actor &&
+            threadActor.youngestFrame.actor.frameLifetimePool) {
+          actor = threadActor.youngestFrame.actor.frameLifetimePool.get(actorId);
+        }
+
         if (!actor)
             return null;
 
@@ -552,7 +567,9 @@ DebuggerLib.breakNow = function(context)
         // but we might want to change what global to use here.
         var global = context.getCurrentGlobal();
         var dbgGlobal = this.getInactiveDebuggeeGlobal(context, global);
-        return dbgGlobal.evalInGlobal("debugger;");
+        return dbgGlobal.executeInGlobal ?
+            dbgGlobal.executeInGlobal("debugger;") :
+            dbgGlobal.evalInGlobal("debugger;");
     }
 };
 
diff --git a/extension/content/firebug/debugger/script/breakNotification.js b/extension/content/firebug/debugger/script/breakNotification.js
index 09ebced48e..c4fb0219fd 100644
--- a/extension/content/firebug/debugger/script/breakNotification.js
+++ b/extension/content/firebug/debugger/script/breakNotification.js
@@ -305,6 +305,8 @@ BreakNotification.prototype = domplate(Rep,
         this.listener.onNotificationShow(this);
         return;
 
+        // xxxSebastian: Code is unreachable, therefore commented out
+        /*
         // Animation
         var self = this;
         var delta = Math.max(3, Math.floor(this.box.clientHeight/5));
@@ -326,6 +328,7 @@ BreakNotification.prototype = domplate(Rep,
         }, 15);
 
         return this.box;
+        */
     },
 
     hide: function()
diff --git a/extension/content/firebug/debugger/script/scriptPanel.js b/extension/content/firebug/debugger/script/scriptPanel.js
index 87f0da8dd7..b7faa071c9 100644
--- a/extension/content/firebug/debugger/script/scriptPanel.js
+++ b/extension/content/firebug/debugger/script/scriptPanel.js
@@ -1834,7 +1834,7 @@ ScriptPanel.prototype = Obj.extend(BasePanel,
 
         function failure(result, context)
         {
-            // We are mostly not interested in this evaluation error. It just polutes
+            // We are mostly not interested in this evaluation error. It just pollutes
             // the tracing console.
             // Trace.sysout("scriptPanel.populateInfoTip; ERROR " + result, result);
 
diff --git a/extension/content/firebug/debugger/script/sourceTool.js b/extension/content/firebug/debugger/script/sourceTool.js
index d6fceb6c39..813b291d7a 100644
--- a/extension/content/firebug/debugger/script/sourceTool.js
+++ b/extension/content/firebug/debugger/script/sourceTool.js
@@ -155,7 +155,8 @@ SourceTool.prototype = Obj.extend(new Tool(),
     {
         // Ignore scripts generated from 'clientEvaluate' packets. These scripts are
         // created e.g. as the user is evaluating expressions in the watch window.
-        if (DebuggerLib.isFrameLocationEval(script.url))
+        if (script.introductionType === "debugger eval" ||
+            DebuggerLib.isFrameLocationEval(script.url))
         {
             Trace.sysout("sourceTool.addScript; A script ignored " + script.type +
                 ", " + script.url, script);
@@ -814,7 +815,7 @@ function computeDynamicUrl(script, context)
     // Workaround for issue 7521. Make sure dynamic scripts always have
     // unique URL if the source differs.
     // It solves the problem where eval on the same location (i.e. wrapped
-    // within a fucntion) is used to generate different scripts.
+    // within a function) is used to generate different scripts.
     var sourceFile = context.getSourceFile(uniqueUrl);
     if (sourceFile)
     {
diff --git a/extension/content/firebug/debugger/stack/stackFrame.js b/extension/content/firebug/debugger/stack/stackFrame.js
index 12c91fd409..0dd7db77a7 100644
--- a/extension/content/firebug/debugger/stack/stackFrame.js
+++ b/extension/content/firebug/debugger/stack/stackFrame.js
@@ -354,7 +354,7 @@ StackFrame.removeChromeFrames = function(trace)
     for (var i = 0; i < frames.length; i++)
     {
         var href = frames[i].href;
-        if (href.startsWith("chrome:") || href.startsWith("resource:"))
+        if (!href || href.startsWith("chrome:") || href.startsWith("resource:"))
             continue;
 
         // xxxFlorent: should be reverted if we integrate
diff --git a/extension/content/firebug/firebugui/codemirror.css b/extension/content/firebug/firebugui/codemirror.css
index 23eaf74d44..3fb2f5653a 100644
--- a/extension/content/firebug/firebugui/codemirror.css
+++ b/extension/content/firebug/firebugui/codemirror.css
@@ -126,7 +126,7 @@ div.CodeMirror span.CodeMirror-nonmatchingbracket {color: #f22;}
 }
 
 /* The fake, visible scrollbars. Used to force redraw during scrolling
-   before actuall scrolling happens, thus preventing shaking and
+   before actual scrolling happens, thus preventing shaking and
    flickering artifacts. */
 .CodeMirror-vscrollbar, .CodeMirror-hscrollbar, .CodeMirror-scrollbar-filler, .CodeMirror-gutter-filler {
   position: absolute;
diff --git a/extension/content/firebug/firefox/browserMenu.js b/extension/content/firebug/firefox/browserMenu.js
index 23b597dced..53b586b11c 100644
--- a/extension/content/firebug/firefox/browserMenu.js
+++ b/extension/content/firebug/firefox/browserMenu.js
@@ -436,15 +436,17 @@ var BrowserMenu =
     overlayFirefoxMenu: function(doc)
     {
         // Firefox page context menu
-        $menupopupOverlay(doc, $(doc, "contentAreaContextMenu"), [
-            $menuseparator(doc),
-            $menuitem(doc, {
-                id: "menu_firebug_firebugInspect",
-                label: "firebug.InspectElementWithFirebug",
-                command: "cmd_firebug_inspect",
-                "class": "menuitem-iconic"
-            })
-        ]);
+        if (!this.browserOverlay.isMultiprocessEnabled()) {
+            $menupopupOverlay(doc, $(doc, "contentAreaContextMenu"), [
+                $menuseparator(doc),
+                $menuitem(doc, {
+                    id: "menu_firebug_firebugInspect",
+                    label: "firebug.InspectElementWithFirebug",
+                    command: "cmd_firebug_inspect",
+                    "class": "menuitem-iconic"
+                })
+            ]);
+        }
 
         // Firefox view menu
         $menupopupOverlay(doc, $(doc, "menu_viewPopup"),
diff --git a/extension/content/firebug/firefox/browserOverlay.css b/extension/content/firebug/firefox/browserOverlay.css
index 89904ac131..ed67e15991 100644
--- a/extension/content/firebug/firefox/browserOverlay.css
+++ b/extension/content/firebug/firefox/browserOverlay.css
@@ -200,6 +200,10 @@ fbMultiprocessNotificationPanel {
     -moz-binding: url("chrome://firebug/content/firefox/multiprocessNotificationPanel.xml#panel");
 }
 
+fbNewMultiprocessNotificationPanel {
+    -moz-binding: url("chrome://firebug/content/firefox/newMultiprocessNotificationPanel.xml#panel");
+}
+
 fbAuroraNotificationPanel {
     -moz-binding: url("chrome://firebug/content/firefox/auroraNotificationPanel.xml#panel");
 }
@@ -210,12 +214,30 @@ fbUpgradeNotificationPanel {
 
 fbUpgradeNotificationPanel .iconbox,
 fbAuroraNotificationPanel .iconbox,
+fbNewMultiprocessNotificationPanel .iconbox,
 fbMultiprocessNotificationPanel .iconbox {
     padding-right: 10px;
 }
 
+fbNewMultiprocessNotificationPanel .closeButton {
+    background-image: url(chrome://firebug/skin/mac/close.svg);
+    width: 13px;
+    height: 13px;
+    border: none;
+    cursor: pointer;
+}
+
+fbNewMultiprocessNotificationPanel .closeButton:hover {
+    filter: url(resource://firebugui/filters.svg#darken);
+}
+
+fbNewMultiprocessNotificationPanel .closeButton:active {
+    filter: url(resource://firebugui/filters.svg#deepDarken);
+}
+
 fbUpgradeNotificationPanel .desc,
 fbAuroraNotificationPanel .desc,
+fbNewMultiprocessNotificationPanel .desc,
 fbMultiprocessNotificationPanel .desc {
     max-width: 300px;
 }
@@ -225,24 +247,29 @@ fbUpgradeNotificationPanel .title {
     font-size: 16px;
 }
 
+fbNewMultiprocessNotificationPanel .warn,
 fbMultiprocessNotificationPanel .warn {
     max-width: 275px;
 }
 
+fbNewMultiprocessNotificationPanel .warn,
 fbMultiprocessNotificationPanel .warn {
     color: gray;
 }
 
+fbNewMultiprocessNotificationPanel .warningbox,
 fbMultiprocessNotificationPanel .warningbox {
     margin-top: 15px;
 }
 
+fbNewMultiprocessNotificationPanel .warningicon,
 fbMultiprocessNotificationPanel .warningicon {
     margin-right: 4px;
 }
 
 fbUpgradeNotificationPanel .progress,
 fbAuroraNotificationPanel .progress,
+fbNewMultiprocessNotificationPanel .progress,
 fbMultiprocessNotificationPanel .progress {
     margin: 8px;
 }
diff --git a/extension/content/firebug/firefox/browserOverlay.js b/extension/content/firebug/firefox/browserOverlay.js
index 424eaf90f5..67e6617a93 100644
--- a/extension/content/firebug/firefox/browserOverlay.js
+++ b/extension/content/firebug/firefox/browserOverlay.js
@@ -13,9 +13,11 @@ define([
     "firebug/firefox/browserMenu",
     "firebug/firefox/browserToolbar",
     "firebug/lib/system",
+    "firebug/lib/devtools",
+    "firebug/lib/channel",
 ],
 function(FBTrace, Options, Locale, Events, Arr, Str, Xpcom, BrowserOverlayLib,
-    BrowserCommands, BrowserMenu, BrowserToolbar, System) {
+    BrowserCommands, BrowserMenu, BrowserToolbar, System, DevTools, Channel) {
 
 // ********************************************************************************************* //
 // Constants
@@ -150,13 +152,18 @@ BrowserOverlay.prototype =
     {
         // Special case for e10s enabled browser.
         if (this.isMultiprocessEnabled()) {
+            this.showNewMultiprocessNotification();
+            return;
+        }
+
+        /*if (this.isMultiprocessEnabled()) {
             this.showMultiprocessNotification();
             return;
         }
         else if (this.isAuroraChannel()) {
             this.showAuroraNotification();
             return;
-        }
+        }*/
 
         if (this.win.Firebug.waitingForFirstLoad)
             return;
@@ -439,9 +446,10 @@ BrowserOverlay.prototype =
     getVersion: function()
     {
         var versionURL = "chrome://firebug/content/branch.properties";
-        var ioService = Cc["@mozilla.org/network/io-service;1"].getService(Ci.nsIIOService);
 
-        var channel = ioService.newChannel(versionURL, null, null);
+        var loadingPrincipal = servicesScope.Services.scriptSecurityManager.getSystemPrincipal();
+
+        var channel = Channel.new(versionURL);
         var input = channel.open();
         var sis = Cc["@mozilla.org/scriptableinputstream;1"].
             createInstance(Ci.nsIScriptableInputStream);
@@ -748,6 +756,47 @@ BrowserOverlay.prototype =
         panel.open();
     },
 
+    showNewMultiprocessNotification: function()
+    {
+        if (Options.get("noMultiprocessMessage"))
+        {
+          this.toggleDevTools();
+          return;
+        }
+
+        this.oldTheme = Options.getPref("devtools", "theme");
+        this.oldTheme = (this.oldTheme == "firebug") ? "light" : this.oldTheme;
+        this.domPanelWasEnabled = Options.getPref("devtools", "dom.enabled");
+
+        var popupSet = $(this.doc, "mainPopupSet");
+        var panel = this.doc.querySelector("fbNewMultiprocessNotificationPanel");
+        if (!panel)
+        {
+            panel = this.doc.createElement("fbNewMultiprocessNotificationPanel");
+            panel.setAttribute("opendevtoolscommand", "Firebug.browserOverlay.onOpenDevTools(event, 'fbMultiprocessNotificationPanel')");
+            panel.setAttribute("disablecommand", "Firebug.browserOverlay.onDisableE10s(event)");
+            panel.setAttribute("activatefirebugtheme", "Firebug.browserOverlay.onActivateFirebugTheme(event)");
+
+            popupSet.appendChild(panel);
+        }
+
+        let firebugTheme = Options.get("activateFirebugTheme");
+        panel.firebugTheme.checked = firebugTheme;
+
+        //panel.notAgain.checked = false;
+
+        if (firebugTheme)
+        {
+            this.activateFirebugTheme("firebug");
+            this.enableDomPanel(true);
+        }
+
+        panel.internationalize(Locale);
+        panel.open();
+
+        this.toggleDevTools(true);
+    },
+
     onDisableE10s: function(event)
     {
       Events.cancelEvent(event);
@@ -757,9 +806,82 @@ BrowserOverlay.prototype =
       Options.setPref("browser.tabs", "remote.autostart", false);
       Options.setPref("browser.tabs", "remote.autostart.1", false);
 
+      var panel = this.doc.querySelector("fbNewMultiprocessNotificationPanel");
+      //Options.set("noMultiprocessMessage", panel.notAgain.checked);
+      Options.set("noMultiprocessMessage", true);
+
       restartFirefox();
     },
 
+    onOpenDevTools: function(event)
+    {
+      Events.cancelEvent(event);
+
+      var panel = this.doc.querySelector("fbNewMultiprocessNotificationPanel");
+      //Options.set("noMultiprocessMessage", panel.notAgain.checked);
+      Options.set("noMultiprocessMessage", true);
+
+      panel.close();
+    },
+
+    onActivateFirebugTheme: function(event) {
+      var panel = this.doc.querySelector("fbNewMultiprocessNotificationPanel");
+      var newTheme = panel.firebugTheme.checked ? "firebug" : this.oldTheme;
+
+      // Remember state of the checkbox.
+      Options.set("activateFirebugTheme", panel.firebugTheme.checked);
+
+      // Activate/deactivate Firebug theme.
+      this.activateFirebugTheme(newTheme);
+
+      // When Firebug theme is activated show also the DOM panel.
+      this.enableDomPanel(panel.firebugTheme.checked);
+    },
+
+    activateFirebugTheme: function(newTheme) {
+      var oldTheme = Options.getPref("devtools", "theme");
+
+      Options.setPref("devtools", "theme", newTheme);
+
+      let data = {
+        pref: "devtools.theme",
+        newValue: newTheme,
+        oldValue: oldTheme
+      };
+
+      DevTools.gDevTools.emit("pref-changed", data);
+    },
+
+    enableDomPanel: function(enable) {
+      var enableDomPanel = enable ? true : this.domPanelWasEnabled;
+      var currValue = Options.getPref("devtools", "dom.enabled");
+      if (currValue == enableDomPanel) {
+        return;
+      }
+
+      Options.setPref("devtools", "dom.enabled", enableDomPanel);
+
+      if (enableDomPanel) {
+        DevTools.gDevTools.emit("tool-registered", "dom");
+      } else {
+        let toolDefinition = DevTools.gDevTools._tools.get("dom");
+        DevTools.gDevTools.emit("tool-unregistered", toolDefinition);
+      }
+    },
+
+    toggleDevTools: function(forceOpen) {
+      var toolbox = getToolbox(this.win);
+      if (toolbox && forceOpen) {
+        return;
+      }
+
+      if (toolbox) {
+        destroyToolbox(this.win);
+      } else {
+        showToolbox(this.win);
+      }
+    },
+
     onUpgradeFirebug: function(event, panelId)
     {
         Events.cancelEvent(event);
@@ -852,6 +974,8 @@ BrowserOverlay.prototype =
     },
 };
 
+// Helpers
+
 function findFirebugUpdate(callback)
 {
     var xhr = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"].createInstance();
@@ -892,11 +1016,41 @@ function findFirebugUpdate(callback)
     xhr.send(null);
 }
 
-function restartFirefox() {
+function restartFirefox()
+{
     Cc["@mozilla.org/toolkit/app-startup;1"].getService(Ci.nsIAppStartup).
         quit(Ci.nsIAppStartup.eRestart | Ci.nsIAppStartup.eAttemptQuit);
 }
 
+function getCurrentTab(win)
+{
+    let browserDoc = win.top.document;
+    let browser = browserDoc.getElementById("content");
+    return browser.selectedTab;
+}
+
+function showToolbox(win)
+{
+    let tab = getCurrentTab(win);
+    let target = DevTools.devtools.TargetFactory.forTab(tab);
+    return DevTools.gDevTools.showToolbox(target);
+}
+
+function destroyToolbox(win)
+{
+    let toolbox = getToolbox(win);
+    if (toolbox) {
+      return toolbox.destroy();
+    }
+}
+
+function getToolbox(win)
+{
+    let tab = getCurrentTab(win);
+    let target = DevTools.devtools.TargetFactory.forTab(tab);
+    return DevTools.gDevTools.getToolbox(target);
+}
+
 // ********************************************************************************************* //
 // Registration
 
diff --git a/extension/content/firebug/firefox/external-editors/editors.js b/extension/content/firebug/firefox/external-editors/editors.js
index 80c3b992d8..7860ade017 100644
--- a/extension/content/firebug/firefox/external-editors/editors.js
+++ b/extension/content/firebug/firefox/external-editors/editors.js
@@ -211,7 +211,7 @@ EditorManager.prototype =
 
         try
         {
-            var editors = this._data.map(function(x) x.id);
+            var editors = this._data.map(x => x.id);
             prefs.setCharPref(this._prefName, editors.join(","));
         }
         catch (exc)
diff --git a/extension/content/firebug/firefox/newMultiprocessNotificationPanel.xml b/extension/content/firebug/firefox/newMultiprocessNotificationPanel.xml
new file mode 100644
index 0000000000..53b04db771
--- /dev/null
+++ b/extension/content/firebug/firefox/newMultiprocessNotificationPanel.xml
@@ -0,0 +1,148 @@
+<?xml version="1.0"?>
+<!-- See license.txt for terms of usage -->
+
+<bindings xmlns="http://www.mozilla.org/xbl"
+    xmlns:xbl="http://www.mozilla.org/xbl"
+    xmlns:xul="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
+    xmlns:html="http://www.w3.org/1999/xhtml">
+
+<binding id="panel">
+    <resources>
+      <stylesheet src="chrome://global/skin/notification.css"/>
+    </resources>
+    <content>
+        <xul:panel anonid="panel" norestorefocus="true" noautofocus="true"
+            ignorekeys="true" role="presentation" type="arrow" class="panel">
+            <xul:hbox>
+               <xul:vbox class="iconbox">
+                   <xul:image src="chrome://firebug/skin/firebug64.png"/>
+               </xul:vbox>
+               <xul:vbox>
+                    <xul:hbox class="warningbox"></xul:hbox>
+
+                    <xul:description anonid="desc" class="desc" />
+
+                    <xul:hbox class="warningbox"></xul:hbox>
+
+                    <xul:label anonid="learnMore"
+                        class="text-link popup-notification-learnmore-link learnMore"
+                        href="https://getfirebug.com/unifying-firebug-and-firefox-devtools"/>
+
+                    <xul:hbox class="warningbox"></xul:hbox>
+
+                    <xul:description anonid="desc3" class="desc" />
+
+                    <xul:hbox class="warningbox">
+                        <xul:vbox>
+                            <xul:checkbox anonid="firebugTheme" checked="true"
+                                xbl:inherits="oncommand=activatefirebugtheme" />
+                        </xul:vbox>
+                    </xul:hbox>
+
+                    <!-- <xul:hbox class="warningbox">
+                        <xul:vbox>
+                            <xul:checkbox anonid="notAgain" checked="false" />
+                        </xul:vbox>
+                    </xul:hbox> -->
+
+                    <xul:hbox class="warningbox" style="height: 10px;"></xul:hbox>
+
+                    <xul:hbox align="right">
+                        <xul:progressmeter anonid="progress" class="progress"
+                            mode="determined" value="0" collapsed="true"/>
+                        <xul:spacer width="20px" />
+                        <xul:button anonid="opendevtools" type="menu-button"
+                            xbl:inherits="oncommand=opendevtoolscommand"
+                            class="popup-notification-menubutton">
+                            <xul:menupopup>
+                                <xul:menuitem anonid="disable"
+                                    xbl:inherits="oncommand=disablecommand"/>
+                            </xul:menupopup>
+                        </xul:button>
+                    </xul:hbox>
+                </xul:vbox>
+                <xul:vbox>
+                    <xul:image class="closeButton" anonid="closeButton"/>
+                </xul:vbox>
+             </xul:hbox>
+        </xul:panel>
+    </content>
+
+    <implementation>
+        <constructor><![CDATA[
+        ]]></constructor>
+
+        <method name="internationalize">
+            <parameter name="Locale" />
+            <body><![CDATA[
+                var desc = document.getAnonymousElementByAttribute(this, "anonid", "desc");
+                desc.textContent = Locale.$STR("multiprocess.description");
+
+                var desc3 = document.getAnonymousElementByAttribute(this, "anonid", "desc3");
+                desc3.textContent = Locale.$STR("multiprocess.description3");
+
+                var learnMore = document.getAnonymousElementByAttribute(this, "anonid", "learnMore");
+                learnMore.textContent = Locale.$STR("multiprocess.learnMore");
+
+                //var notAgain = document.getAnonymousElementByAttribute(this, "anonid", "notAgain");
+                //notAgain.label = Locale.$STR("multiprocess.notAgain");
+
+                var openDevToolsButton = document.getAnonymousElementByAttribute(this, "anonid", "opendevtools");
+                openDevToolsButton.label = Locale.$STR("multiprocess.openDevTools");
+
+                var disableMenu = document.getAnonymousElementByAttribute(this, "anonid", "disable");
+                disableMenu.label = Locale.$STR("multiprocess.disable");
+
+                this.firebugTheme.label = Locale.$STR("multiprocess.activateFirebugTheme");
+
+                var closeButton = document.getAnonymousElementByAttribute(this, "anonid", "closeButton");
+                closeButton.addEventListener('click', this.close.bind(this), false);
+            ]]></body>
+        </method>
+
+        <method name="open">
+            <body><![CDATA[
+                var offsetY = 0;
+                var offsetX = 0;
+                var target = document.getElementById("nav-bar-customization-target");
+
+                var startButton = document.getElementById("firebug-button");
+                if (startButton) {
+                    var style = document.defaultView.getComputedStyle(startButton.button);
+                    offsetY = parseInt(style["padding-bottom"]);
+                    offsetX = parseInt(style["width"])/2;
+                    target = startButton.button;
+                }
+
+                var panel = document.getAnonymousElementByAttribute(this, "anonid", "panel");
+                panel.openPopup(target, "after_end", -offsetX, -offsetY, false, false);
+            ]]></body>
+        </method>
+
+        <method name="close">
+            <body><![CDATA[
+                var panel = document.getAnonymousElementByAttribute(this, "anonid", "panel");
+                panel.hidePopup();
+            ]]></body>
+        </method>
+
+        <property name="openDevToolsButton">
+            <getter><![CDATA[
+                return document.getAnonymousElementByAttribute(this, "anonid", "opendevtools");
+            ]]></getter>
+        </property>
+
+        <property name="notAgain">
+            <getter><![CDATA[
+                return document.getAnonymousElementByAttribute(this, "anonid", "notAgain");
+            ]]></getter>
+        </property>
+
+        <property name="firebugTheme">
+            <getter><![CDATA[
+                return document.getAnonymousElementByAttribute(this, "anonid", "firebugTheme");
+            ]]></getter>
+        </property>
+    </implementation>
+</binding>
+</bindings>
diff --git a/extension/content/firebug/html/eventsPanel.js b/extension/content/firebug/html/eventsPanel.js
index 2ad1c5568b..966efb9467 100644
--- a/extension/content/firebug/html/eventsPanel.js
+++ b/extension/content/firebug/html/eventsPanel.js
@@ -260,7 +260,7 @@ EventsPanel.prototype = Obj.extend(Firebug.Panel,
             return null;
         try
         {
-            // Pattern match on the occurance of '<minified name>.event.<funcName>.apply'.
+            // Pattern match on the occurrence of '<minified name>.event.<funcName>.apply'.
             var matches = /\b([a-zA-Z_$][a-zA-Z0-9_$]*)\.event\.(dispatch|handle)\.apply/.exec(src);
             var jqName = (matches && matches[1]) || "";
             dbgEnv = dbgEnv.find(jqName);
diff --git a/extension/content/firebug/html/htmlModule.js b/extension/content/firebug/html/htmlModule.js
index dbafb424a5..5a731eacc8 100644
--- a/extension/content/firebug/html/htmlModule.js
+++ b/extension/content/firebug/html/htmlModule.js
@@ -102,7 +102,7 @@ var HTMLModule = Obj.extend(Module,
 // Mutation Breakpoints
 
 /**
- * @class Represents {@link Firebug.Debugger} listener. This listener is reponsible for
+ * @class Represents {@link Firebug.Debugger} listener. This listener is responsible for
  * providing a list of mutation-breakpoints into the Breakpoints side-panel.
  */
 HTMLModule.DebuggerListener =
diff --git a/extension/content/firebug/html/inspector.js b/extension/content/firebug/html/inspector.js
index 5c0a62ce1c..716e298c5b 100644
--- a/extension/content/firebug/html/inspector.js
+++ b/extension/content/firebug/html/inspector.js
@@ -1501,7 +1501,7 @@ function attachStyles(context, doc)
         highlightStyleCache.set(doc, style);
     }
 
-    // Cater for the possiblity that someone might have removed our stylesheet.
+    // Cater for the possibility that someone might have removed our stylesheet.
     if (!style.parentNode)
         Css.addStyleSheet(doc, style);
 }
diff --git a/extension/content/firebug/lib/channel.js b/extension/content/firebug/lib/channel.js
new file mode 100644
index 0000000000..1139e42a0a
--- /dev/null
+++ b/extension/content/firebug/lib/channel.js
@@ -0,0 +1,46 @@
+/* See license.txt for terms of usage */
+
+define([
+],
+function() {
+
+"use strict";
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cu = Components.utils;
+
+var appInfo = Cc["@mozilla.org/xre/app-info;1"]
+    .getService(Ci.nsIXULAppInfo);
+var versionComparator = Cc["@mozilla.org/xpcom/version-comparator;1"]
+    .getService(Ci.nsIVersionComparator);
+var fx47OrEarlier = (versionComparator.compare(appInfo.version, "47a1") < 0);
+
+const ioService = Cc["@mozilla.org/network/io-service;1"].getService(Ci.nsIIOService);
+
+Cu.import("resource://gre/modules/NetUtil.jsm");
+
+// ********************************************************************************************* //
+// Module
+
+var Channel = {};
+
+Channel.new = function(url)
+{
+    if (fx47OrEarlier)
+    {
+        return ioService.newChannel(url, null, null);
+    }
+    else
+    {
+      return NetUtil.newChannel({
+          uri: url,
+          loadUsingSystemPrincipal: true
+      });
+    }
+}
+
+return Channel;
+
+// ********************************************************************************************* //
+});
diff --git a/extension/content/firebug/lib/devtools.js b/extension/content/firebug/lib/devtools.js
new file mode 100644
index 0000000000..85ad112e97
--- /dev/null
+++ b/extension/content/firebug/lib/devtools.js
@@ -0,0 +1,158 @@
+/* See license.txt for terms of usage */
+/*global define:1, Components:1, Window:1*/
+
+define([
+],
+function() {
+
+"use strict";
+
+var Cu = Components.utils;
+var Cc = Components.classes;
+var Ci = Components.interfaces;
+
+var appInfo = Cc["@mozilla.org/xre/app-info;1"].getService(Ci.nsIXULAppInfo);
+var versionComparator = Cc["@mozilla.org/xpcom/version-comparator;1"].getService(Ci.nsIVersionComparator);
+
+var exports = {};
+
+/**
+ * Allows importing a JS module (Firefox platform) and specify alternative locations
+ * to keep backward compatibility in case when the module location changes.
+ * It helps Firebug to support multiple Firefox versions.
+ *
+ * @param {Array} locations List of URLs to try when importing the module.
+ * @returns Scope of the imported module or an empty scope if module wasn't successfully loaded.
+ */
+function safeImport(...args) {
+  for (var i=0; i<args.length; i++) {
+    try {
+      return Cu["import"](args[i], {});
+    }
+    catch (err) {
+    }
+  }
+  return {};
+}
+
+exports.safeImport = safeImport;
+
+/**
+ * Allows requiring a devtools module and specify alternative locations
+ * to keep backward compatibility in case when the module location changes.
+ * It helps Firebug to support multiple Firefox versions.
+ *
+ * @param {Object} devtools Reference to DevTools module.
+ * @param {Array} locations List of URLs to try when importing the module.
+ * @returns Scope of the imported module or an empty scope if module wasn't successfully loaded.
+ */
+function safeRequire(devtools, ...args) {
+  for (var i=0; i<args.length; i++) {
+    try {
+      return devtools["require"](args[i]);
+    }
+    catch (err) {
+    }
+  }
+  return {};
+}
+
+exports.safeRequire = safeRequire;
+
+/**
+ * Allows importing or requiring a devtools module and specify alternative
+ * locations to keep backward compatibility when the module location changes.
+ */
+function safeGet(devtools, ...args) {
+  for (var i=0; i<args.length; i++) {
+    var url = args[i];
+    if (url.startsWith("resource://")) {
+      try {
+        return Cu["import"](url, {});
+      }
+      catch (err) {
+      }
+    } else if (url.startsWith("devtools/")) {
+      try {
+        return devtools["require"](url);
+      }
+      catch (err) {
+      }
+    }
+  }
+  return {};
+}
+
+exports.safeGet = safeGet;
+
+// Support for new devtools modules path.
+// See also:
+// * https://wiki.mozilla.org/DevTools/Hacking
+// * https://github.com/jryans/devtools-migrate/blob/master/README.md
+// * https://developer.mozilla.org/en-US/docs/Tools/Contributing
+// * https://bugzilla.mozilla.org/show_bug.cgi?id=912121
+// * https://bugzilla.mozilla.org/show_bug.cgi?id=1203159
+
+const devtools = exports.devtools = safeImport(
+  "resource://devtools/shared/Loader.jsm",
+  "resource://gre/modules/devtools/shared/Loader.jsm",
+  "resource://gre/modules/devtools/Loader.jsm"
+).devtools;
+
+exports.DevToolsUtils = safeRequire(devtools,
+  "devtools/shared/DevToolsUtils",
+  "devtools/toolkit/DevToolsUtils"
+);
+
+exports.makeInfallible = exports.DevToolsUtils.makeInfallible;
+
+exports.gDevTools = safeGet(devtools,
+  "devtools/client/framework/devtools",
+  "resource:///devtools/client/framework/gDevTools.jsm",
+  "resource:///modules/devtools/client/framework/gDevTools.jsm",
+  "resource:///modules/devtools/gDevTools.jsm"
+).gDevTools;
+
+exports.EventEmitter = safeRequire(devtools,
+  "devtools/shared/event-emitter",
+  "devtools/toolkit/event-emitter"
+);
+
+exports.ToolSidebar = safeRequire(devtools,
+  "devtools/client/framework/sidebar",
+  "devtools/framework/sidebar"
+).ToolSidebar;
+
+exports.DebuggerServer = safeGet(devtools,
+  "devtools/server/main",
+  "resource://gre/modules/devtools/dbg-server.jsm"
+).DebuggerServer;
+
+exports.DebuggerClient = safeGet(devtools,
+  "devtools/shared/client/main",
+  "resource://gre/modules/devtools/dbg-client.jsm"
+).DebuggerClient;
+
+exports.DevToolsWorker = safeGet(devtools,
+  "devtools/shared/worker/worker",
+  "devtools/toolkit/shared/worker"
+).DevToolsWorker;
+
+exports.ScratchpadManager = safeImport(
+  "resource://devtools/client/scratchpad/scratchpad-manager.jsm",
+  "resource:///modules/devtools/client/scratchpad/scratchpad-manager.jsm",
+  "resource:///modules/devtools/scratchpad-manager.jsm"
+).ScratchpadManager;
+
+exports.require = exports.devtools["require"];
+
+// Pretty print worker
+var fx43OrEarlier = (versionComparator.compare(appInfo.version, "44a1") < 0);
+exports.prettyPrintWorkerUrl = fx43OrEarlier ?
+  "resource://gre/modules/devtools/server/actors/pretty-print-worker.js" :
+  "resource://devtools/server/actors/pretty-print-worker.js";
+
+return exports;
+
+// ********************************************************************************************* //
+});
diff --git a/extension/content/firebug/lib/domplate.js b/extension/content/firebug/lib/domplate.js
index 44644810eb..9a8ed9bbfc 100644
--- a/extension/content/firebug/lib/domplate.js
+++ b/extension/content/firebug/lib/domplate.js
@@ -91,7 +91,7 @@ DomplateTag.prototype =
      * Initializer for DOM templates. Called to create new Functions objects like TR, TD,
      * OBJLINK, etc. See defineTag
      *
-     * @param args keyword argments for the template, the {} brace stuff after the tag name,
+     * @param args keyword arguments for the template, the {} brace stuff after the tag name,
      *      eg TR({...}, TD(...
      * @param oldTag a nested tag, eg the TD tag in TR({...}, TD(...
      */
@@ -750,7 +750,7 @@ DomplateLoop.prototype = copyObject(DomplateTag.prototype,
         var iterName;
         if (this.iter instanceof Parts)
         {
-            // We have a function with optional aruments or just one variable
+            // We have a function with optional arguments or just one variable
             var part = this.iter.parts[0];
 
             // Join our function arguments or variables
@@ -868,7 +868,7 @@ function parseParts(str)
     if (!index)
     {
         // Double quotes in strings need to be escaped (see issue 6710)
-        return str.replace("\\", "\\\\", "g").replace('"', '\\"', "g");
+        return str.replace(/\\/g, "\\\\").replace(/"/g, '\\"');
     }
 
     // If we have data after our last matched index we append it here as the final step
diff --git a/extension/content/firebug/lib/http.js b/extension/content/firebug/lib/http.js
index 24f8a0f135..80bf39b86c 100644
--- a/extension/content/firebug/lib/http.js
+++ b/extension/content/firebug/lib/http.js
@@ -5,9 +5,10 @@ define([
     "firebug/lib/trace",
     "firebug/lib/deprecated",
     "firebug/debugger/stack/stackFrame",
-    "firebug/lib/string"
+    "firebug/lib/string",
+    "firebug/lib/channel",
 ],
-function(Xpcom, FBTrace, Deprecated, StackFrame, Str) {
+function(Xpcom, FBTrace, Deprecated, StackFrame, Str, Channel) {
 
 "use strict";
 
@@ -17,9 +18,9 @@ function(Xpcom, FBTrace, Deprecated, StackFrame, Str) {
 const Cc = Components.classes;
 const Ci = Components.interfaces;
 const Cr = Components.results;
+const Cu = Components.utils;
 
 const NS_SEEK_SET = Ci.nsISeekableStream.NS_SEEK_SET;
-const ioService = Cc["@mozilla.org/network/io-service;1"].getService(Ci.nsIIOService);
 
 var Http = {};
 
@@ -96,7 +97,7 @@ Http.getResource = function(aURL, ignoreMissing)
 {
     try
     {
-        var channel = ioService.newChannel(aURL, null, null);
+        var channel = Channel.new(aURL);
         var input = channel.open();
 
         return Http.readFromStream(input);
@@ -351,7 +352,7 @@ Http.safeGetXHRResponseText = function(xhr)
 };
 
 // ********************************************************************************************* //
-// IP Adress and port number (Requires Gecko 5).
+// IP Address and port number (Requires Gecko 5).
 
 Http.safeGetLocalAddress = function(request)
 {
diff --git a/extension/content/firebug/lib/json.js b/extension/content/firebug/lib/json.js
index c81ad32a37..9015bd63a9 100644
--- a/extension/content/firebug/lib/json.js
+++ b/extension/content/firebug/lib/json.js
@@ -70,9 +70,10 @@ Json.parseJSONString = function(jsonString, originURL)
     }
     catch (exc) {}
 
-    // Give up if we don't have valid start, to avoid some unnecessary overhead.
+    // Give up if we don't have valid start, to avoid some unnecessary overhead,
+    // and if we don't start with comments (pseudoJsonToJson is meant to strip them).
     first = firstNonWs(jsonString);
-    if (first !== "[" && first !== "{" && isNaN(first) && first !== '"')
+    if (first !== "[" && first !== "{" && isNaN(first) && first !== '"' && first !== "/")
         return null;
 
     // Remove JavaScript comments, quote non-quoted identifiers, and merge
diff --git a/extension/content/firebug/lib/object.js b/extension/content/firebug/lib/object.js
index c227e83cc5..391acd095b 100644
--- a/extension/content/firebug/lib/object.js
+++ b/extension/content/firebug/lib/object.js
@@ -4,9 +4,10 @@ define([
     "firebug/lib/trace",
     "firebug/lib/xpcom",
     "firebug/lib/array",
-    "firebug/lib/string"
+    "firebug/lib/string",
+    "firebug/lib/devtools",
 ],
-function(FBTrace, Xpcom, Arr, Str) {
+function(FBTrace, Xpcom, Arr, Str, DevTools) {
 
 "use strict";
 
@@ -219,14 +220,15 @@ Obj.isNonNativeGetter = function(obj, propName)
 {
     try
     {
-        var scope = {};
-        Cu.import("resource://gre/modules/devtools/WebConsoleUtils.jsm", scope);
+        var {Utils} = DevTools.safeRequire(DevTools.devtools,
+          "devtools/shared/webconsole/utils",
+          "devtools/toolkit/webconsole/utils");
 
-        if (scope.WebConsoleUtils.isNonNativeGetter)
+        if (Utils.isNonNativeGetter)
         {
             Obj.isNonNativeGetter = function(obj, propName)
             {
-                return scope.WebConsoleUtils.isNonNativeGetter(obj, propName);
+                return Utils.isNonNativeGetter.isNonNativeGetter(obj, propName);
             };
 
             return Obj.isNonNativeGetter(obj, propName);
diff --git a/extension/content/firebug/lib/search.js b/extension/content/firebug/lib/search.js
index c127c3a478..fb3286b5bd 100644
--- a/extension/content/firebug/lib/search.js
+++ b/extension/content/firebug/lib/search.js
@@ -174,7 +174,7 @@ Search.ReversibleIterator = function(length, start, reverse)
  *
  * @constructor
  * @param {String} literal Text to search for
- * @param {Boolean} reverse Truthy to preform a reverse search, falsy to perform a forward seach
+ * @param {Boolean} reverse Truthy to preform a reverse search, falsy to perform a forward search
  * @param {Boolean} caseSensitive Truthy to perform a case sensitive search, falsy to perform
  * a case insensitive search.
  */
diff --git a/extension/content/firebug/lib/string.js b/extension/content/firebug/lib/string.js
index b89091987a..eb520d34c8 100644
--- a/extension/content/firebug/lib/string.js
+++ b/extension/content/firebug/lib/string.js
@@ -406,8 +406,8 @@ Str.stripNewLines = function(value)
 
 Str.escapeSingleQuoteJS = function(value)
 {
-    return value.replace("\\", "\\\\", "g").replace(/\r/gm, "\\r")
-                .replace(/\n/gm, "\\n").replace("'", "\\'", "g");
+    return value.replace(/\\/g, "\\\\").replace(/\r/gm, "\\r")
+                .replace(/\n/gm, "\\n").replace(/'/g, "\\'");
 };
 
 Str.reverseString = function(value)
@@ -417,8 +417,8 @@ Str.reverseString = function(value)
 
 Str.escapeJS = function(value)
 {
-    return value.replace("\\", "\\\\", "g").replace(/\r/gm, "\\r")
-        .replace(/\n/gm, "\\n").replace('"', '\\"', "g");
+    return value.replace(/\\/g, "\\\\").replace(/\r/gm, "\\r")
+        .replace(/\n/gm, "\\n").replace(/"/g, '\\"');
 };
 
 Str.cropString = function(text, limit, alternativeText)
diff --git a/extension/content/firebug/lib/url.js b/extension/content/firebug/lib/url.js
index 0fbb6ee9ec..7c29760dff 100644
--- a/extension/content/firebug/lib/url.js
+++ b/extension/content/firebug/lib/url.js
@@ -343,9 +343,7 @@ Url.isAbsoluteUrl = function(url)
 
 Url.absoluteURL = function(url, baseURL)
 {
-    // Replace "/./" with "/" using regular expressions (don't use string since /./
-    // can be treated as regular expressoin too, see 3551).
-    return Url.absoluteURLWithDots(url, baseURL).replace(/\/\.\//, "/", "g");
+    return Url.absoluteURLWithDots(url, baseURL).replace(/\/\.\//g, "/");
 };
 
 Url.absoluteURLWithDots = function(url, baseURL)
@@ -419,7 +417,7 @@ Url.normalizeURL = function(url)
 
     // Normalize path traversals (a/b/../c -> a/c).
     while (url.indexOf("/../") !== -1 && url[0] != "/")
-        url = url.replace(/[^\/]+\/\.\.\//g, "");
+        url = url.replace(/[^\/]+\/+\.\.\//g, "");
 
     // Issue 1496, avoid #
     url = url.replace(/#.*/, "");
diff --git a/extension/content/firebug/net/netCacheReader.js b/extension/content/firebug/net/netCacheReader.js
index b87be2a985..f0549ec07e 100644
--- a/extension/content/firebug/net/netCacheReader.js
+++ b/extension/content/firebug/net/netCacheReader.js
@@ -279,8 +279,16 @@ function onDescriptorAvailable(netProgress, file, descriptor)
 {
     Trace.sysout("netCacheReader.onDescriptorAvailable; file.href: " + file.href, descriptor);
 
+    // Avoid error message in the Console panel.
+    // See also: https://github.com/firebug/firebug/issues/8003
+    let descriptorDataSize = 0;
+    try {
+        descriptorDataSize = descriptor.dataSize;
+    } catch (err) {
+    }
+
     if (file.size <= 0)
-        file.size = descriptor.dataSize;
+        file.size = descriptorDataSize;
 
     if (descriptor.lastModified && descriptor.lastFetched &&
         descriptor.lastModified < Math.floor(file.startTime/1000))
@@ -304,7 +312,7 @@ function onDescriptorAvailable(netProgress, file, descriptor)
         },
         {
             name: "Data Size",
-            value: descriptor.dataSize
+            value: descriptorDataSize
         },
         {
             name: "Fetch Count",
diff --git a/extension/content/firebug/net/netPanel.js b/extension/content/firebug/net/netPanel.js
index a2106f0e3f..db03d0318e 100644
--- a/extension/content/firebug/net/netPanel.js
+++ b/extension/content/firebug/net/netPanel.js
@@ -888,7 +888,7 @@ NetPanel.prototype = Obj.extend(ActivablePanel,
             var tbody = this.table.querySelector(".netTableBody");
 
             // xxxHonza: Fake first row (shold be renamed, but it's a hack anyway).
-            // There is no way to insert a row befor the current first row in a table.
+            // There is no way to insert a row before the current first row in a table.
             // See Domplate.insertRows() comment for more details.
             NetRequestEntry.footerTag.insertRows({}, tbody);
 
@@ -1059,7 +1059,7 @@ NetPanel.prototype = Obj.extend(ActivablePanel,
     {
         var tbody = this.table.querySelector(".netTableBody");
 
-        // XXXjoe Don't update rows whose phase is done and layed out already
+        // XXXjoe Don't update rows whose phase is done and laid out already
         var phase;
         for (var row = tbody.firstChild; row; row = row.nextSibling)
         {
diff --git a/extension/content/firebug/net/netProgress.js b/extension/content/firebug/net/netProgress.js
index 0f7950183e..189b3a539f 100644
--- a/extension/content/firebug/net/netProgress.js
+++ b/extension/content/firebug/net/netProgress.js
@@ -956,6 +956,7 @@ NetProgress.prototype =
 function logTime(file, title, time)
 {
     // xxxHonza: just for debugging purposes.
+    /*
     return;
 
     if (!file._timings)
@@ -969,6 +970,7 @@ function logTime(file, title, time)
         index: ++file._timings.counter,
         time: time
     });
+    */
 }
 
 // ********************************************************************************************* //
diff --git a/extension/content/firebug/net/netReps.js b/extension/content/firebug/net/netReps.js
index 7fbd222158..befb420626 100644
--- a/extension/content/firebug/net/netReps.js
+++ b/extension/content/firebug/net/netReps.js
@@ -1063,7 +1063,7 @@ Firebug.NetMonitor.NetInfoBody = domplate(Rep, new EventSource(),
                 Firebug.NetMonitor.NetInfoHeaders.renderHeaders(headersText,
                     file.responseHeaders, "ResponseHeaders");
 
-                // If the request comes from the BFCache do not display reponse headers.
+                // If the request comes from the BFCache do not display response headers.
                 // There is not real response from the server and all headers come from
                 // the cache. So, the user should see the 'Response Headers From Cache'
                 // section (see issue 5573).
diff --git a/extension/content/firebug/net/netUtils.js b/extension/content/firebug/net/netUtils.js
index eba7eb172d..0a932244db 100644
--- a/extension/content/firebug/net/netUtils.js
+++ b/extension/content/firebug/net/netUtils.js
@@ -240,7 +240,7 @@ var NetUtils =
 
     getResponseText: function(file, context)
     {
-        // The response can be also empty string so, check agains "undefined".
+        // The response can be also empty string so, check against "undefined".
         return (typeof(file.responseText) != "undefined") ?
             file.responseText :
             context.sourceCache.loadText(file.href, file.method, file);
@@ -371,7 +371,7 @@ var NetUtils =
      * The logic is as follows:
      * 1) If the request is an XHR, return 'xhr' as category
      * 2) Otherwise use the file extension to guess the MIME type.
-     *    This is prefered since MIME types in HTTP requests are often wrong.
+     *    This is preferred since MIME types in HTTP requests are often wrong.
      *    This part is based on the 'mimeExtensionMap' map.
      * 3) If the file extension is missing or unknown, try to get the MIME type
      *    from the HTTP request object.
@@ -389,7 +389,7 @@ var NetUtils =
      * The logic is as follows:
      * 1) If the request is an XHR, add 'xhr' as category
      * 2) Use the file extension to guess the MIME type.
-     *    This is prefered since MIME types in HTTP requests are often wrong.
+     *    This is preferred since MIME types in HTTP requests are often wrong.
      *    This part is based on the 'mimeExtensionMap' map.
      * 3) If the file extension is missing or unknown, try to get the MIME type
      *    from the HTTP request object.
@@ -408,7 +408,7 @@ var NetUtils =
             categories.push("xhr");
 
         // Guess mime-type according to the file extension. Using file extension
-        // is prefered way since mime-types in HTTP requests are often wrong.
+        // is preferred way since mime-types in HTTP requests are often wrong.
         var mimeType = this.getMimeType(null, file.href);
 
         // If no luck with file extension, let's try to get the mime-type from
diff --git a/extension/content/firebug/net/sourceCache.js b/extension/content/firebug/net/sourceCache.js
index 67a1c898c2..4704da81e8 100644
--- a/extension/content/firebug/net/sourceCache.js
+++ b/extension/content/firebug/net/sourceCache.js
@@ -8,24 +8,24 @@ define([
     "firebug/lib/url",
     "firebug/lib/http",
     "firebug/lib/options",
-    "firebug/lib/string"
+    "firebug/lib/string",
+    "firebug/lib/channel"
 ],
-function(EventSource, Obj, Firebug, Xpcom, Url, Http, Options, Str) {
+function(EventSource, Obj, Firebug, Xpcom, Url, Http, Options, Str, Channel) {
 
 // ********************************************************************************************* //
 // Constants
 
 const Cc = Components.classes;
 const Ci = Components.interfaces;
-const nsIIOService = Ci.nsIIOService;
+const Cu = Components.utils;
+
 const nsIRequest = Ci.nsIRequest;
 const nsICachingChannel = Ci.nsICachingChannel;
 const nsIScriptableInputStream = Ci.nsIScriptableInputStream;
 const nsIUploadChannel = Ci.nsIUploadChannel;
 const nsIHttpChannel = Ci.nsIHttpChannel;
 
-const IOService = Cc["@mozilla.org/network/io-service;1"];
-const ioService = IOService.getService(nsIIOService);
 const ScriptableInputStream = Cc["@mozilla.org/scriptableinputstream;1"];
 const chromeReg = Xpcom.CCSV("@mozilla.org/chrome/chrome-registry;1", "nsIToolkitChromeRegistry");
 
@@ -214,7 +214,7 @@ Firebug.SourceCache.prototype = Obj.extend(new EventSource(),
         var channel;
         try
         {
-            channel = ioService.newChannel(url, null, null);
+            channel = Channel.new(url);
             channel.loadFlags |= LOAD_FROM_CACHE | LOAD_BYPASS_LOCAL_CACHE_IF_BUSY;
 
             if (method && (channel instanceof nsIHttpChannel))
diff --git a/extension/content/firebug/net/spy.js b/extension/content/firebug/net/spy.js
index 65cab8ab4b..283bce1339 100644
--- a/extension/content/firebug/net/spy.js
+++ b/extension/content/firebug/net/spy.js
@@ -908,7 +908,7 @@ function onHTTPSpyAbort(spy)
 
     updateLogRow(spy);
 
-    // Notify Net pane about a request beeing aborted.
+    // Notify Net pane about a request being aborted.
     // xxxHonza: the net panel shoud find out this itself.
     var netProgress = spy.context.netProgress;
     if (netProgress)
diff --git a/extension/content/firebug/net/tabCache.js b/extension/content/firebug/net/tabCache.js
index f7578e68b7..ceac59771e 100644
--- a/extension/content/firebug/net/tabCache.js
+++ b/extension/content/firebug/net/tabCache.js
@@ -18,17 +18,18 @@ define([
     "firebug/trace/traceListener",
     "firebug/net/sourceCache",
     "firebug/lib/options",
+    "firebug/lib/channel",
 ],
 function(ActivableModule, Obj, Firebug, Xpcom, HttpRequestObserver, HttpResponseObserver, Locale,
-    Events, Url, Http, Str, Win, JSONViewerModel, TraceModule, TraceListener, SourceCache, Options) {
+    Events, Url, Http, Str, Win, JSONViewerModel, TraceModule, TraceListener, SourceCache,
+    Options, Channel) {
 
 // ********************************************************************************************* //
 // Constants
 
 const Cc = Components.classes;
 const Ci = Components.interfaces;
-
-const ioService = Cc["@mozilla.org/network/io-service;1"].getService(Ci.nsIIOService);
+const Cu = Components.utils;
 
 // List of text content types. These content-types are cached.
 var contentTypes =
@@ -440,7 +441,7 @@ Firebug.TabCache.prototype = Obj.extend(SourceCache.prototype,
             if (url === "<unknown>")
                 return [Locale.$STR("message.sourceNotAvailableFor") + ": " + url];
 
-            var channel = ioService.newChannel(url, null, null);
+            var channel = Channel.new(url);
 
             // These flag combination doesn't repost the request.
             channel.loadFlags = Ci.nsIRequest.LOAD_FROM_CACHE |
diff --git a/extension/content/firebug/remoting/debuggerClient.js b/extension/content/firebug/remoting/debuggerClient.js
index c8ecb1d7d7..9a8209c8b6 100644
--- a/extension/content/firebug/remoting/debuggerClient.js
+++ b/extension/content/firebug/remoting/debuggerClient.js
@@ -6,12 +6,13 @@ define([
     "firebug/lib/object",
     "firebug/lib/options",
     "firebug/lib/events",
+    "firebug/lib/devtools",
     "firebug/chrome/tabWatcher",
     "firebug/chrome/firefox",
     "firebug/chrome/window",
     "firebug/remoting/tabClient",
 ],
-function(Firebug, FBTrace, Obj, Options, Events, TabWatcher, Firefox, Win, TabClient) {
+function(Firebug, FBTrace, Obj, Options, Events, DevTools, TabWatcher, Firefox, Win, TabClient) {
 
 "use strict";
 
@@ -24,11 +25,12 @@ var Trace = FBTrace.to("DBG_DEBUGGERCLIENT");
 var TraceConn = FBTrace.to("DBG_CONNECTION");
 var TraceError = FBTrace.toError();
 
-var dbgClientScope = {};
-var dbgServerScope = {};
-
-Cu["import"]("resource://gre/modules/devtools/dbg-client.jsm", dbgClientScope);
-Cu["import"]("resource://gre/modules/devtools/dbg-server.jsm", dbgServerScope);
+var dbgClientScope = {
+  DebuggerClient: DevTools.DebuggerClient
+};
+var dbgServerScope = {
+  DebuggerServer: DevTools.DebuggerServer
+};
 
 // ********************************************************************************************* //
 // Module Implementation
@@ -109,10 +111,10 @@ var DebuggerClient = Obj.extend(Firebug.Module,
             {
                 // The debugger server might be already initialized either by Firebug
                 // in another browser window or by built-in devtools.
-                if (!DebuggerServer.initialized)
+                if (!dbgServerScope.DebuggerServer.initialized)
                 {
-                    DebuggerServer.init(function () { return true; });
-                    DebuggerServer.addBrowserActors();
+                    dbgServerScope.DebuggerServer.init(function () { return true; });
+                    dbgServerScope.DebuggerServer.addBrowserActors();
                 }
             }
             catch (e)
@@ -123,7 +125,7 @@ var DebuggerClient = Obj.extend(Firebug.Module,
 
         this.transport = (this.isRemoteDebugger) ?
             debuggerSocketConnect(Options.get("remoteHost"), Options.get("remotePort")) :
-            DebuggerServer.connectPipe();
+            dbgServerScope.DebuggerServer.connectPipe();
 
         // Load Firebug actors. If Firebug is running server side these actors
         // should also be loaded.
@@ -405,6 +407,12 @@ var DebuggerClient = Obj.extend(Firebug.Module,
 
     onThreadAttached: function(context)
     {
+        // "newSource" events are emitted by thread-actor now.
+        // https://hg.mozilla.org/integration/mozilla-inbound/rev/152f968b6b13
+        // https://github.com/firebug/firebug/issues/7918
+        // https://bugzilla.mozilla.org/show_bug.cgi?id=1171967
+        context.activeThread.addListener("newSource", this.newSource);
+
         this.dispatch("onThreadAttached", [context, false]);
 
         Firebug.dispatchEvent(context.browser, "onThreadAttached");
@@ -412,6 +420,8 @@ var DebuggerClient = Obj.extend(Firebug.Module,
 
     onThreadDetached: function(context)
     {
+        context.activeThread.removeListener("newSource");
+
         this.dispatch("onThreadDetached", [context]);
 
         Firebug.dispatchEvent(context.browser, "onThreadDetached");
diff --git a/extension/content/firebug/server/server.js b/extension/content/firebug/server/server.js
index 5e8504a206..736e3ad0a3 100644
--- a/extension/content/firebug/server/server.js
+++ b/extension/content/firebug/server/server.js
@@ -2,8 +2,9 @@
 
 define([
     "firebug/lib/trace",
+    "firebug/lib/devtools",
 ],
-function(FBTrace) {
+function(FBTrace, DevTools) {
 
 // xxxHonza: FBTrace isn't available when loading from within bootstrap.js
 // The default FBTrace implementation should buffer all logs that are fired
@@ -16,6 +17,8 @@ var Cc = Components.classes;
 var Ci = Components.interfaces;
 var Cu = Components.utils;
 
+var DebuggerServer = DevTools.DebuggerServer;
+
 // ********************************************************************************************* //
 // Module
 
@@ -28,8 +31,6 @@ var Server =
     {
         try
         {
-            Cu.import("resource:///modules/devtools/dbg-server.jsm");
-
             DebuggerServer.init(function() { return true; });
 
             // Add built-in actors (like e.g. debugger actors)
diff --git a/extension/defaults/preferences/firebug.js b/extension/defaults/preferences/firebug.js
index 7df4e05f14..a1f9b08944 100644
--- a/extension/defaults/preferences/firebug.js
+++ b/extension/defaults/preferences/firebug.js
@@ -28,6 +28,10 @@ pref("extensions.firebug.hideDefaultInspector", false);
 pref("extensions.firebug.delayLoad", true);
 pref("extensions.firebug.clearAnnotationsConfirmation", true);
 
+// Multiprocess Notification
+pref("extensions.firebug.noMultiprocessMessage", false);
+pref("extensions.firebug.activateFirebugTheme", true);
+
 // Remoting
 pref("extensions.firebug.serverHost", "localhost");
 pref("extensions.firebug.serverPort", 5999);
diff --git a/extension/install.rdf b/extension/install.rdf
index 482fd4997e..69ed7fdce7 100644
--- a/extension/install.rdf
+++ b/extension/install.rdf
@@ -5,16 +5,17 @@
 
   <Description about="urn:mozilla:install-manifest">
     <em:id>firebug@software.joehewitt.com</em:id>
-    <em:version>2.0.11</em:version>
+    <em:version>2.0.19</em:version>
     <em:type>2</em:type>
     <em:bootstrap>true</em:bootstrap>
+    <em:multiprocessCompatible>true</em:multiprocessCompatible>
 
     <!-- Any suitably modern toolkit application -->
     <em:targetApplication>
       <Description>
         <em:id>toolkit@mozilla.org</em:id>
         <em:minVersion>30.0a1</em:minVersion>
-        <em:maxVersion>41.0</em:maxVersion>
+        <em:maxVersion>54.0</em:maxVersion>
       </Description>
     </em:targetApplication>
 
@@ -23,7 +24,7 @@
       <Description>
         <em:id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}</em:id>
         <em:minVersion>30.0a1</em:minVersion>
-        <em:maxVersion>41.0</em:maxVersion>
+        <em:maxVersion>54.0</em:maxVersion>
       </Description>
     </em:targetApplication>
 
diff --git a/extension/install.rdf.tpl.xml b/extension/install.rdf.tpl.xml
index cbfe6cbbc9..e0bf39e51f 100644
--- a/extension/install.rdf.tpl.xml
+++ b/extension/install.rdf.tpl.xml
@@ -8,13 +8,14 @@
     <em:version>@VERSION@@RELEASE@</em:version>
     <em:type>2</em:type>
     <em:bootstrap>true</em:bootstrap>
+    <em:multiprocessCompatible>true</em:multiprocessCompatible>
 
     <!-- Any suitably modern toolkit application -->
     <em:targetApplication>
       <Description>
         <em:id>toolkit@mozilla.org</em:id>
         <em:minVersion>30.0a1</em:minVersion>
-        <em:maxVersion>41.0</em:maxVersion>
+        <em:maxVersion>54.0</em:maxVersion>
       </Description>
     </em:targetApplication>
 
@@ -23,7 +24,7 @@
       <Description>
         <em:id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}</em:id>
         <em:minVersion>30.0a1</em:minVersion>
-        <em:maxVersion>41.0</em:maxVersion>
+        <em:maxVersion>54.0</em:maxVersion>
       </Description>
     </em:targetApplication>
 
diff --git a/extension/locale/en-US/multiprocess-notification.properties b/extension/locale/en-US/multiprocess-notification.properties
index d62e42b98d..ec4708d232 100644
--- a/extension/locale/en-US/multiprocess-notification.properties
+++ b/extension/locale/en-US/multiprocess-notification.properties
@@ -1,14 +1,24 @@
-# LOCALIZATION NOTE (multiprocess.description, multiprocess.learnMore, multiprocess.warning,
+# LOCALIZATION NOTE (multiprocess.description, multiprocess.description3, multiprocess.learnMore, multiprocess.warning,
 # multiprocess.upgrade, multiprocess.disable, multiprocess.cancel):
 # Label used in a notification panel that is displayed when the user clicks on Firebug start
 # button in multiprocess Firefox browser (e10s enabled browser).
-multiprocess.description=Firebug 2 doesn't work with multiprocess Firefox (e10s). So you need to either disable e10s or upgrade to Firebug 3 alpha.
-multiprocess.learnMore=Learn more...
+multiprocess.description=The next version of Firebug has been integrated directly into the Firefox Developer Tools for increased performance and stability.
+multiprocess.description3=This change includes an updated Inspector and new Performance, Storage, and Memory tools, all using the Firebug theme you’re familiar with.
+multiprocess.learnMore=Learn more about the changes...
 multiprocess.warning=Firebug 3 alpha is based on the built-in Firefox developer tools so Firebug 2 addons don't work just yet, however turning off e10s should only be a temporary measure since it brings performance, stability and security advantages.
 multiprocess.upgrade=Upgrade and Restart
-multiprocess.disable=Disable e10s and Restart
+multiprocess.disable=Enable old Firebug and disable e10s (requires restart)
 multiprocess.cancel=Cancel
 
+# LOCALIZATION NOTE (multiprocess.notAgain, multiprocess.description2,
+# multiprocess.openDevTools, multiprocess.warning2): Label used in a new notification panel
+# that is displayed when the user clicks on Firebug start button in multiprocess
+# Firefox browser (e10s enabled browser).
+multiprocess.description2=We've ported many Firebug features into built-in tools in order to support existing Firebug users so, go ahead and check it out!
+multiprocess.openDevTools=Don’t show this message again
+multiprocess.warning2=Turning off e10s should only be a temporary measure since it brings performance, stability and security advantages.
+multiprocess.notAgain=Do not display this message again
+
 # LOCALIZATION NOTE (aurora.description, aurora.description2, aurora.notnow, aurora.nothanks):
 # Label used in a notification panel that is displayed when the user clicks on Firebug start
 # button in Aurora (Firefox) channel.
@@ -26,3 +36,8 @@ upgrade.tip.upgradeFirebug=Upgrade to Firebug 3 (for testers)
 # Label used in a notification panel that is displayed when the user wants to explicitly upgrade Firebug.
 upgrade.description=Firebug 3 alpha is available for testing
 upgrade.description2=Firebug 3 is based on the built-in Firefox developer tools so it works with the performance, stability and security advantages coming with multiprocess Firefox (also known as e10s), however Firebug 2 addons don't work with Firebug 3 yet.
+
+# LOCALIZATION NOTE (multiprocess.activateFirebugTheme):
+# Label used in a notification panel that is displayed when the user wants to explicitly upgrade Firebug.
+# The label belongs to a checkbox allowing to activate/deactivate Firebug theme for built-in DevTools
+multiprocess.activateFirebugTheme=Activate the Firebug theme
diff --git a/extension/modules/firebug-trace-service.js b/extension/modules/firebug-trace-service.js
index 489c6f9b17..40ffc082a5 100644
--- a/extension/modules/firebug-trace-service.js
+++ b/extension/modules/firebug-trace-service.js
@@ -138,7 +138,7 @@ TracerWrapper.prototype =
 
         // Create FBTrace proxy. As soon as FBTrace console is available it'll forward
         // all calls to it.
-        return Proxy.create(
+        return new Proxy({},
         {
             get: function(target, name)
             {
diff --git a/extension/modules/gcli.js b/extension/modules/gcli.js
index 6b8827a4fc..58d2d3339c 100644
--- a/extension/modules/gcli.js
+++ b/extension/modules/gcli.js
@@ -123,10 +123,23 @@ var commands = [];
 
 function addCommand(command)
 {
+    // API for registering GCLI commands has changed in Firefox 42
+    // The new API are not supported at the moment.
+    // Some pointers:
+    // All modules in
+    // https://dxr.mozilla.org/mozilla-central/source/toolkit/devtools/gcli/commands
+    // export their items, for example:
+    // https://dxr.mozilla.org/mozilla-central/source/toolkit/devtools/gcli/commands/cookie.js#54
+    // And the code that does most of the loading for built-in commands is:
+    // https://dxr.mozilla.org/mozilla-central/source/toolkit/devtools/gcli/commands/index.js
+    // Test with a helper API:
+    // https://dxr.mozilla.org/mozilla-central/source/browser/devtools/commandline/test/helpers.js#469
+
     if (scope.gcli.addCommand)
         scope.gcli.addCommand(command);
-    else
+    else if (scope.gcli.addItems)
         scope.gcli.addItems([command]);
+
     commands.push(command);
 }
 
diff --git a/extension/modules/locale.js b/extension/modules/locale.js
index 9734714bce..4a16117258 100644
--- a/extension/modules/locale.js
+++ b/extension/modules/locale.js
@@ -42,7 +42,7 @@ var Locale = {};
  * $STR("Label"); - search for key "Label" within the firebug.properties file
  *                 and returns its value. If the key doesn't exist returns "Label".
  *
- * $STR("Button Label"); - search for key "Button_Label" withing the firebug.properties
+ * $STR("Button Label"); - search for key "Button_Label" within the firebug.properties
  *                        file. If the key doesn't exist returns "Button Label".
  *
  * $STR("net.Response Header"); - search for key "net.Response_Header". If the key doesn't
@@ -65,7 +65,7 @@ Locale.$STR = function(name, bundle)
     if (!name)
         return "";
 
-    var strKey = name.replace(" ", "_", "g");
+    var strKey = name.replace(/ /g, "_");
 
     if (!PrefLoader.getPref("useDefaultLocale"))
     {
@@ -100,14 +100,14 @@ Locale.$STR = function(name, bundle)
     var index = name.lastIndexOf(".");
     if (index > 0 && name.charAt(index-1) != "\\")
         name = name.substr(index + 1);
-    name = name.replace("_", " ", "g");
+    name = name.replace(/_/g, " ");
 
     return name;
 };
 
 Locale.$STRF = function(name, args, bundle)
 {
-    var strKey = name.replace(" ", "_", "g");
+    var strKey = name.replace(/ /g, "_");
 
     if (!PrefLoader.getPref("useDefaultLocale"))
     {
diff --git a/extension/modules/require-debug.js b/extension/modules/require-debug.js
index eecaab708e..1074614c42 100644
--- a/extension/modules/require-debug.js
+++ b/extension/modules/require-debug.js
@@ -67,8 +67,7 @@ require.execCbOFF = function (name)
                             (typeof value == "function"/* || typeof value == "object"*/))
                         {
                                 var funcName = name + "_" + prop;
-                                funcName = funcName.replace("/", "_", "g");
-                                funcName = funcName.replace("-", "_", "g");
+                                funcName = funcName.replace(/[\/\-]/g, "_");
                                 var namedFunction = eval("(function(){ return function " + funcName +
                                     "(){return true;} })()");
                                 value.displayName = namedFunction;
@@ -183,4 +182,4 @@ require.onError = function(exc)
 {
     require.onDebug.apply(require, arguments);
     throw exc;
-};
\ No newline at end of file
+};
diff --git a/extension/update.rdf.tpl.xml b/extension/update.rdf.tpl.xml
index 5637fff4f9..f8b4bf16df 100644
--- a/extension/update.rdf.tpl.xml
+++ b/extension/update.rdf.tpl.xml
@@ -12,7 +12,7 @@
             <r:Description>
               <id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}</id>
               <minVersion>30.0a1</minVersion>
-              <maxVersion>41.0</maxVersion>
+              <maxVersion>54.0</maxVersion>
               <updateLink>https://getfirebug.com/releases/firebug/@VERSION@/@LEAF@</updateLink>
               <updateInfoURL>https://getfirebug.com/updateInfo/firebug2.0.xml</updateInfoURL>
             </r:Description>
diff --git a/tests/FBTest/content/testResultTabView.js b/tests/FBTest/content/testResultTabView.js
index 8a18927667..ed1e94c4fb 100644
--- a/tests/FBTest/content/testResultTabView.js
+++ b/tests/FBTest/content/testResultTabView.js
@@ -372,8 +372,8 @@ var TestResultTabView = domplate(
 // ********************************************************************************************* //
 
 /**
- * This template displays a parse-erros that can occurs when parsing
- * expected and acuall results (see compare method).
+ * This template displays a parse-errors that can occurs when parsing
+ * expected and actuall results (see compare method).
  *
  * @domplate
  */
diff --git a/tests/content/commandLine/4391/jquery-latest.js b/tests/content/commandLine/4391/jquery-latest.js
index 9a13ab960e..01dcd52833 100644
--- a/tests/content/commandLine/4391/jquery-latest.js
+++ b/tests/content/commandLine/4391/jquery-latest.js
@@ -1997,7 +1997,7 @@ jQuery.fn.extend({
 					classNames = value.split( rspace );
 
 				while ( (className = classNames[ i++ ]) ) {
-					// check each className given, space seperated list
+					// check each className given, space separated list
 					state = isBool ? state : !self.hasClass( className );
 					self[ state ? "addClass" : "removeClass" ]( className );
 				}
@@ -3652,7 +3652,7 @@ var chunker = /((?:\((?:\([^()]+\)|[^()]+)+\)|\[(?:\[[^\[\]]*\]|['"][^'"]*['"]|[
 	rNonWord = /\W/;
 
 // Here we check if the JavaScript engine is using some sort of
-// optimization where it does not always call our comparision
+// optimization where it does not always call our comparison
 // function. If that is the case, discard the hasDuplicate value.
 //   Thus far that includes Google Chrome.
 [0, 0].sort(function() {
@@ -4630,7 +4630,7 @@ if ( document.documentElement.compareDocumentPosition ) {
 	};
 }
 
-// Utility function for retreiving the text value of an array of DOM nodes
+// Utility function for retrieving the text value of an array of DOM nodes
 Sizzle.getText = function( elems ) {
 	var ret = "", elem;
 
@@ -7769,7 +7769,7 @@ if ( jQuery.support.ajax ) {
 							xml;
 
 						// Firefox throws exceptions when accessing properties
-						// of an xhr when a network error occured
+						// of an xhr when a network error occurred
 						// http://helpful.knobs-dials.com/index.php/Component_returned_failure_code:_0x80040111_(NS_ERROR_NOT_AVAILABLE)
 						try {
 
diff --git a/tests/content/commandLine/api/dirxml.html b/tests/content/commandLine/api/dirxml.html
index b91f8de20b..870c5351af 100644
--- a/tests/content/commandLine/api/dirxml.html
+++ b/tests/content/commandLine/api/dirxml.html
@@ -15,7 +15,7 @@ <h1>Command Line API: dirxml</h1>
 
 <ol>
 <li>Open Firebug and enable the Console panel.</li>
-<li>Execute teh following expression in the command line:<br/>
+<li>Execute the following expression in the command line:<br/>
 <code style="color:green">dirxml(document.getElementById("content"));</code></li>
 <li>The console panel should display a following XML log:</li>
 </ol>
diff --git a/tests/content/console/1693/issue1693.js b/tests/content/console/1693/issue1693.js
index a1e331ad70..220559d6d9 100644
--- a/tests/content/console/1693/issue1693.js
+++ b/tests/content/console/1693/issue1693.js
@@ -54,7 +54,7 @@ function onDataComplete(e)
                 for (var i = 0; i < 80000; i++)
                     responseText += i + " ";
 
-                // Compare expected and actuall (displayed) response text.
+                // Compare expected and actual (displayed) response text.
                 var text1 = responseText.substr(0, limit);
                 var text2 = responseBody.textContent.substr(0, limit);
                 FBTest.compare(text1, text2, "The response text must be properly displayed");
diff --git a/tests/content/console/6356/jquery-1.9.1.js b/tests/content/console/6356/jquery-1.9.1.js
index e2c203fe97..2d8494017e 100644
--- a/tests/content/console/6356/jquery-1.9.1.js
+++ b/tests/content/console/6356/jquery-1.9.1.js
@@ -4186,7 +4186,7 @@ setDocument = Sizzle.setDocument = function( node ) {
 		// Regex strategy adopted from Diego Perini
 		assert(function( div ) {
 			// Select is set to empty string on purpose
-			// This is to test IE's treatment of not explictly
+			// This is to test IE's treatment of not explicitly
 			// setting a boolean content attribute,
 			// since its presence should be enough
 			// http://bugs.jquery.com/ticket/12359
diff --git a/tests/content/console/spy/2462/issue2462.js b/tests/content/console/spy/2462/issue2462.js
index 97b088d4c1..228a63eb67 100644
--- a/tests/content/console/spy/2462/issue2462.js
+++ b/tests/content/console/spy/2462/issue2462.js
@@ -9,7 +9,7 @@ function runTest()
                 classes: "logRow logRow-spy error loaded"
             };
 
-            // Asynchronously wait for the request beeing displayed.
+            // Asynchronously wait for the request being displayed.
             FBTest.waitForDisplayedElement("console", options, function(logRow)
             {
                 FBTest.testDone();
diff --git a/tests/content/dom/sidePanel/sidePanel.html b/tests/content/dom/sidePanel/sidePanel.html
index 39bb4f37e4..5819b58bfc 100644
--- a/tests/content/dom/sidePanel/sidePanel.html
+++ b/tests/content/dom/sidePanel/sidePanel.html
@@ -14,7 +14,7 @@ <h1>Existence of the DOM side panel</h1>
                 <h3>Steps to reproduce</h3>
                 <ol>
                     <li>Open Firebug</li>
-                    <li>Switch to the <em>HTML</em> panel and checkt DOM side panel is availble</li>
+                    <li>Switch to the <em>HTML</em> panel and checkt DOM side panel is available</li>
                     <li>Selecte the DOM side panel and check it displayes some properties</li>
                 </ol>
             </section>
diff --git a/tests/content/examples/exampleNet1.js b/tests/content/examples/exampleNet1.js
index abc4e1a032..489107f199 100644
--- a/tests/content/examples/exampleNet1.js
+++ b/tests/content/examples/exampleNet1.js
@@ -9,7 +9,7 @@ function runTest()
                 classes: "netRow category-xhr hasHeaders loaded"
             };
 
-            // Asynchronously wait for the request beeing displayed.
+            // Asynchronously wait for the request being displayed.
             FBTest.waitForDisplayedElement("net", options, function(netRow)
             {
                 var options = {
diff --git a/tests/content/firebug.html b/tests/content/firebug.html
index 0c3d78c36e..6ba805e285 100644
--- a/tests/content/firebug.html
+++ b/tests/content/firebug.html
@@ -348,7 +348,7 @@
     {group: "script",             uri: "script/4213/issue4213.js",                desc: "Script panel's location button is not updated", testPage: "script/4213/issue4213.html"},
     {group: "script",             uri: "script/4724/issue4724.js",                desc: "&quot;Disable Breakpoint&quot; is not checked on disabled breakpoints", testPage: "script/4724/issue4724.html"},
     {group: "script",             uri: "script/4816/issue4816.js",                desc: "Script panel claims No JavaScript when it means you're stopped on a breakpoint on some other tab", testPage: "script/4816/issue4816.html"},
-    {group: "script",             uri: "script/4818/issue4818.js",                desc: "frame.eval fails for everthing but the newest frame of the stack", testPage: "script/4818/issue4818.html"},
+    {group: "script",             uri: "script/4818/issue4818.js",                desc: "frame.eval fails for everything but the newest frame of the stack", testPage: "script/4818/issue4818.html"},
     {group: "script",             uri: "script/4932/issue4932.js",                desc: "The Script panel shows No Javascript on this page even if they are scripts within an iframe", testPage: "script/4932/issue4932.html"},
     {group: "script",             uri: "script/5044/issue5044.js",                desc: "Shortcut for Break On Next", testPage: "script/5044/issue5044.html"},
     {group: "script",             uri: "script/6476/issue6476.js",                desc: "Change directive for sourceURL", testPage: "script/6476/issue6476.html"},
diff --git a/tests/content/html/events/5440/jquery-1.5.js b/tests/content/html/events/5440/jquery-1.5.js
index 5c99a8d4a8..219c7c23f2 100644
--- a/tests/content/html/events/5440/jquery-1.5.js
+++ b/tests/content/html/events/5440/jquery-1.5.js
@@ -1815,7 +1815,7 @@ jQuery.fn.extend({
 					classNames = value.split( rspaces );
 
 				while ( (className = classNames[ i++ ]) ) {
-					// check each className given, space seperated list
+					// check each className given, space separated list
 					state = isBool ? state : !self.hasClass( className );
 					self[ state ? "addClass" : "removeClass" ]( className );
 				}
@@ -3272,7 +3272,7 @@ var chunker = /((?:\((?:\([^()]+\)|[^()]+)+\)|\[(?:\[[^\[\]]*\]|['"][^'"]*['"]|[
 	baseHasDuplicate = true;
 
 // Here we check if the JavaScript engine is using some sort of
-// optimization where it does not always call our comparision
+// optimization where it does not always call our comparison
 // function. If that is the case, discard the hasDuplicate value.
 //   Thus far that includes Google Chrome.
 [0, 0].sort(function() {
@@ -4234,7 +4234,7 @@ if ( document.documentElement.compareDocumentPosition ) {
 	};
 }
 
-// Utility function for retreiving the text value of an array of DOM nodes
+// Utility function for retrieving the text value of an array of DOM nodes
 Sizzle.getText = function( elems ) {
 	var ret = "", elem;
 
diff --git a/tests/content/html/events/5440/jquery-1.9.js b/tests/content/html/events/5440/jquery-1.9.js
index e2c203fe97..2d8494017e 100644
--- a/tests/content/html/events/5440/jquery-1.9.js
+++ b/tests/content/html/events/5440/jquery-1.9.js
@@ -4186,7 +4186,7 @@ setDocument = Sizzle.setDocument = function( node ) {
 		// Regex strategy adopted from Diego Perini
 		assert(function( div ) {
 			// Select is set to empty string on purpose
-			// This is to test IE's treatment of not explictly
+			// This is to test IE's treatment of not explicitly
 			// setting a boolean content attribute,
 			// since its presence should be enough
 			// http://bugs.jquery.com/ticket/12359
diff --git a/tests/content/net/1308/issue1308-1.6.js b/tests/content/net/1308/issue1308-1.6.js
index e0ba664516..4348e48a84 100644
--- a/tests/content/net/1308/issue1308-1.6.js
+++ b/tests/content/net/1308/issue1308-1.6.js
@@ -12,7 +12,7 @@ function runTest()
                 classes: "netRow category-xhr hasHeaders loaded"
             };
 
-            // Asynchronously wait for the request beeing displayed.
+            // Asynchronously wait for the request being displayed.
             FBTest.waitForDisplayedElement("net", options, function(netRow)
             {
                 var panel = FBTest.getPanel("net");
diff --git a/tests/content/net/2221/issue2221-1.5.js b/tests/content/net/2221/issue2221-1.5.js
index 1ebec9f643..8abf379169 100644
--- a/tests/content/net/2221/issue2221-1.5.js
+++ b/tests/content/net/2221/issue2221-1.5.js
@@ -1,7 +1,7 @@
 // 1) Load Test case page.
 // 2) Enable Net panel
 // 3) Add "load" listener to the target iframe so, the test knows when
-//    the reponse for submitted form is received.
+//    the response for submitted form is received.
 // 4) Check the Post info UI.
 
 var panel = null;
diff --git a/tests/content/net/2221/issue2221.js b/tests/content/net/2221/issue2221.js
index 1b201efb35..bc9908ba4b 100644
--- a/tests/content/net/2221/issue2221.js
+++ b/tests/content/net/2221/issue2221.js
@@ -1,7 +1,7 @@
 // 1) Load Test case page.
 // 2) Enable Net panel
 // 3) Add "load" listener to the target iframe so, the test knows when
-//    the reponse for submitted form is received.
+//    the response for submitted form is received.
 // 4) Check the Post info UI.
 
 var panel = null;
diff --git a/tests/content/net/2696/issue2696.js b/tests/content/net/2696/issue2696.js
index 43c87c9110..458829512d 100644
--- a/tests/content/net/2696/issue2696.js
+++ b/tests/content/net/2696/issue2696.js
@@ -13,7 +13,7 @@ function runTest()
             // 3) Select Net panel
             FBTest.enableNetPanel(() =>
             {
-                // Asynchronously wait for the request beeing displayed.
+                // Asynchronously wait for the request being displayed.
                 FBTest.waitForDisplayedElement("net", null, (netRow) =>
                 {
                     FBTest.ok(netRow, "There must be just one xhr request.");
diff --git a/tests/content/net/369/issue369.htm b/tests/content/net/369/issue369.htm
index 9417e2beb6..e0719beb3d 100644
--- a/tests/content/net/369/issue369.htm
+++ b/tests/content/net/369/issue369.htm
@@ -25,7 +25,7 @@ <h1>Issue #369</h1>
 <button onclick="makeRequest3();">Secure JSON</button>
 <button onclick="makeRequest4();">JSON in a loop</button>
 <button onclick="makeRequest5();">Break in Script</button>
-<button onclick="makeRequest6();">JSON in a funtion 2</button>
+<button onclick="makeRequest6();">JSON in a function 2</button>
 
 <br/><br/>
 
diff --git a/tests/content/net/372/issue372-1.6.js b/tests/content/net/372/issue372-1.6.js
index 2c29d88e68..ae3689909b 100644
--- a/tests/content/net/372/issue372-1.6.js
+++ b/tests/content/net/372/issue372-1.6.js
@@ -10,7 +10,7 @@ function runTest(request)
                 classes: "netRow category-xhr hasHeaders loaded"
             };
 
-            // Asynchronously wait for the request beeing displayed.
+            // Asynchronously wait for the request being displayed.
             FBTest.waitForDisplayedElement("net", options, function(netRow)
             {
                 // Expand the test request with params
diff --git a/tests/content/net/5592/issue5592.js b/tests/content/net/5592/issue5592.js
index d282e01015..0ed960a3bc 100644
--- a/tests/content/net/5592/issue5592.js
+++ b/tests/content/net/5592/issue5592.js
@@ -57,7 +57,7 @@ function executeAndVerify(callback, target, actionID, expected)
         FBTest.executeContextMenuCommand(target, actionID);
     }
 
-    // Data can be copyied into the clipboard asynchronously,
+    // Data can be copied into the clipboard asynchronously,
     // so wait till they are available.
     FBTest.waitForClipboard(expected, executeContextMenuCommand, (text) =>
     {
diff --git a/tests/content/net/700/issue700-1.6.js b/tests/content/net/700/issue700-1.6.js
index 9bbc2971a9..8b1f9d34eb 100644
--- a/tests/content/net/700/issue700-1.6.js
+++ b/tests/content/net/700/issue700-1.6.js
@@ -14,7 +14,7 @@ function runTest()
                 classes: "netRow category-xhr hasHeaders loaded"
             };
 
-            // Asynchronously wait for the request beeing displayed.
+            // Asynchronously wait for the request being displayed.
             FBTest.waitForDisplayedElement("net", options, function(netRow)
             {
                 var panelNode = FBTest.getPanel("net").panelNode;
diff --git a/tests/content/net/activation/activation.js b/tests/content/net/activation/activation.js
index e5c5fc9fcd..193d13d836 100644
--- a/tests/content/net/activation/activation.js
+++ b/tests/content/net/activation/activation.js
@@ -61,7 +61,7 @@ function selectTabAndVerify(tab, callback)
         classes: "netRow category-xhr hasHeaders loaded"
     };
 
-    // Asynchronously wait for the request beeing displayed.
+    // Asynchronously wait for the request being displayed.
     FBTest.waitForDisplayedElement("net", options, function(netRow)
     {
         FBTest.ok(netRow, "There must be one xhr request.");
diff --git a/tests/content/net/listeners/netInfoBodyListener-1.6.js b/tests/content/net/listeners/netInfoBodyListener-1.6.js
index 2cced6d1f2..e2d1a3f594 100644
--- a/tests/content/net/listeners/netInfoBodyListener-1.6.js
+++ b/tests/content/net/listeners/netInfoBodyListener-1.6.js
@@ -12,7 +12,7 @@ function runTest()
                 classes: "netRow category-xhr hasHeaders loaded"
             };
 
-            // Asynchronously wait for the request beeing displayed.
+            // Asynchronously wait for the request being displayed.
             FBTest.waitForDisplayedElement("net", options, function(netRow)
             {
                 var panelNode = FBTest.getPanel("net").panelNode;
diff --git a/tests/content/script/3402/domplate.js b/tests/content/script/3402/domplate.js
index e92654657f..67caabe1f0 100644
--- a/tests/content/script/3402/domplate.js
+++ b/tests/content/script/3402/domplate.js
@@ -62,7 +62,7 @@ DomplateTag.prototype =
 {
     /*
      *  Initializer for DOM templates. Called to create new Functions objects like TR, TD, OBJLINK, etc. See defineTag
-     *  @param args keyword argments for the template, the {} brace stuff after the tag name, eg TR({...}, TD(...
+     *  @param args keyword arguments for the template, the {} brace stuff after the tag name, eg TR({...}, TD(...
      *  @param oldTag a nested tag, eg the TD tag in TR({...}, TD(...
      */
     merge: function(args, oldTag)
diff --git a/tests/content/script/4818/issue4818.html b/tests/content/script/4818/issue4818.html
index eda38f2b88..f2fcae653d 100644
--- a/tests/content/script/4818/issue4818.html
+++ b/tests/content/script/4818/issue4818.html
@@ -1,7 +1,7 @@
 <!DOCTYPE html>
 <html>
 <head>
-    <title>Issue 4818: frame.eval fails for everthing but the newest frame of the stack</title>
+    <title>Issue 4818: frame.eval fails for everything but the newest frame of the stack</title>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
     <link href="../../_common/testcase.css"
         type="text/css" rel="stylesheet"/>
@@ -22,7 +22,7 @@
 </script>
 <header>
     <h1><a href="http://code.google.com/p/fbug/issues/detail?id=4818">Issue 4818</a>:
-        frame.eval fails for everthing but the newest frame of the stack</h1>
+        frame.eval fails for everything but the newest frame of the stack</h1>
 </header>
 <div>
     <section id="description">
diff --git a/tests/content/script/breakpoints/7478/issue7478.js b/tests/content/script/breakpoints/7478/issue7478.js
index fe1605fb11..28f40263ad 100644
--- a/tests/content/script/breakpoints/7478/issue7478.js
+++ b/tests/content/script/breakpoints/7478/issue7478.js
@@ -26,7 +26,7 @@ function runTest()
                                 var conditionEditor = scriptPanel.
                                     panelNode.querySelector(".conditionEditor");
 
-                                FBTest.ok(conditionEditor, "The condtion editor should display to the user.");
+                                FBTest.ok(conditionEditor, "The condition editor should display to the user.");
                                 FBTest.testDone();
                             });
                         }
diff --git a/tests/content/search/6435/issue6435.html b/tests/content/search/6435/issue6435.html
index 0d03c8d827..773520ab7e 100644
--- a/tests/content/search/6435/issue6435.html
+++ b/tests/content/search/6435/issue6435.html
@@ -17,9 +17,9 @@ <h3>Steps to reproduce</h3>
             <li>Open Firebug, select the DOM panel</li>
             <li>Make sure 'Show DOM Properties' option is off.</li>
             <li>Use the search box to search in the panel</li>
-            <li>There should be 4 occurences of 'test' (case insensitive)</li>
-            <li>There should be 2 occurences of 'Test' (case sensitive)</li>
-            <li>There should be 2 occurences of '21' (case sensitive)</li>
+            <li>There should be 4 occurrences of 'test' (case insensitive)</li>
+            <li>There should be 2 occurrences of 'Test' (case sensitive)</li>
+            <li>There should be 2 occurrences of '21' (case sensitive)</li>
         </ol>
     </section>
     <footer>Jan Odvarko, &lt;odvarko@gmail.com&gt;</footer>
diff --git a/tests/content/search/6435/issue6435.js b/tests/content/search/6435/issue6435.js
index 41987c7ff3..6a05990d11 100644
--- a/tests/content/search/6435/issue6435.js
+++ b/tests/content/search/6435/issue6435.js
@@ -17,7 +17,7 @@ function runTest()
                 executeSearchTest("test", false, false, function(counter)
                 {
                     FBTest.compare(4, counter, "There must be precise number " +
-                         "of occurences (4) actual: " + counter);
+                         "of occurrences (4) actual: " + counter);
                     callback();
                 });
             });
@@ -28,7 +28,7 @@ function runTest()
                 executeSearchTest("test", false, true, function(counter)
                 {
                     FBTest.compare(2, counter, "There must be precise number " +
-                        "of occurences (2) actual: " + counter);
+                        "of occurrences (2) actual: " + counter);
                     callback();
                 });
             });
@@ -39,7 +39,7 @@ function runTest()
                 executeSearchTest("21", false, false, function(counter)
                 {
                     FBTest.compare(2, counter, "There must be precise number " +
-                        "of occurences (2) actual: " + counter);
+                        "of occurrences (2) actual: " + counter);
                     callback();
                 });
             });
@@ -71,7 +71,7 @@ function executeSearchTest(text, reverse, caseSensitive, callback)
 
         var match = sel.getRangeAt(0);
 
-        // OK, we have found the first occurence again, so finish the test.
+        // OK, we have found the first occurrence again, so finish the test.
         FBTest.sysout("search.match; ", match);
         if (firstMatch && (firstMatch.compareBoundaryPoints(Range.START_TO_START, match) ||
             firstMatch.compareBoundaryPoints(Range.END_TO_END, match)) == 0)
diff --git a/tests/content/search/6454/issue6454.js b/tests/content/search/6454/issue6454.js
index 6c499a1b2a..1202d75ed7 100644
--- a/tests/content/search/6454/issue6454.js
+++ b/tests/content/search/6454/issue6454.js
@@ -51,7 +51,7 @@ function executeSearchTest(text, reverse, caseSensitive, callback)
 
         var match = sel.getRangeAt(0);
 
-        // OK, we have found the first occurence again, so finish the test.
+        // OK, we have found the first occurrence again, so finish the test.
         FBTest.sysout("search.match; ", match);
         if (firstMatch && (firstMatch.compareBoundaryPoints(Range.START_TO_START, match) ||
             firstMatch.compareBoundaryPoints(Range.END_TO_END, match)) == 0)
diff --git a/tests/content/search/netPanelSearch.js b/tests/content/search/netPanelSearch.js
index 2c1e99af72..feb81d2738 100644
--- a/tests/content/search/netPanelSearch.js
+++ b/tests/content/search/netPanelSearch.js
@@ -82,7 +82,7 @@ function executeSearchTest(text, reverse, caseSensitive, responseBody, callback)
 
         var match = sel.getRangeAt(0);
 
-        // OK, we have found the first occurence again, so finish the test.
+        // OK, we have found the first occurrence again, so finish the test.
         FBTest.sysout("search.match; ", match);
         if (firstMatch && (firstMatch.compareBoundaryPoints(Range.START_TO_START, match) ||
             firstMatch.compareBoundaryPoints(Range.END_TO_END, match)) == 0)
diff --git a/tests/content/test-bot.html b/tests/content/test-bot.html
index 221c384714..cfbba44667 100644
--- a/tests/content/test-bot.html
+++ b/tests/content/test-bot.html
@@ -264,7 +264,7 @@
     {group: "script",             uri: "script/4213/issue4213.js",                desc: "Script panel's location button is not updated", testPage: "script/4213/issue4213.html"},
     //{group: "script",             uri: "script/4724/issue4724.js",                desc: "&quot;Disable Breakpoint&quot; is not checked on disabled breakpoints", testPage: "script/4724/issue4724.html"},
     {group: "script",             uri: "script/4816/issue4816.js",                desc: "Script panel claims No JavaScript when it means you're stopped on a breakpoint on some other tab", testPage: "script/4816/issue4816.html"},
-    {group: "script",             uri: "script/4818/issue4818.js",                desc: "frame.eval fails for everthing but the newest frame of the stack", testPage: "script/4818/issue4818.html"},
+    {group: "script",             uri: "script/4818/issue4818.js",                desc: "frame.eval fails for everything but the newest frame of the stack", testPage: "script/4818/issue4818.html"},
     //{group: "script",             uri: "script/4932/issue4932.js",                desc: "The Script panel shows No Javascript on this page even if they are scripts within an iframe", testPage: "script/4932/issue4932.html"},
     {group: "script/breakpoints", uri: "script/breakpoints/4854/issue4854.js",    desc: "Issue 4854: XHR breakpoints can't be removed from Breakpoints side panel", testPage: "script/breakpoints/4854/issue4854.html"},
     {group: "script/breakpoints", uri: "script/breakpoints/4889/issue4889.js",    desc: "Issue 4889: Folding for breakpoint categories", testPage: "script/breakpoints/4889/issue4889.html"},
diff --git a/trace/FBTrace/chrome/content/lib/domplate.js b/trace/FBTrace/chrome/content/lib/domplate.js
index 38a1143bb9..e06803128e 100644
--- a/trace/FBTrace/chrome/content/lib/domplate.js
+++ b/trace/FBTrace/chrome/content/lib/domplate.js
@@ -89,7 +89,7 @@ DomplateTag.prototype =
      * Initializer for DOM templates. Called to create new Functions objects like TR, TD,
      * OBJLINK, etc. See defineTag
      *
-     * @param args keyword argments for the template, the {} brace stuff after the tag name,
+     * @param args keyword arguments for the template, the {} brace stuff after the tag name,
      *      eg TR({...}, TD(...
      * @param oldTag a nested tag, eg the TD tag in TR({...}, TD(...
      */
@@ -751,7 +751,7 @@ DomplateLoop.prototype = copyObject(DomplateTag.prototype,
         var iterName;
         if (this.iter instanceof Parts)
         {
-            // We have a function with optional aruments or just one variable
+            // We have a function with optional arguments or just one variable
             var part = this.iter.parts[0];
             
             // Join our function arguments or variables
diff --git a/trace/FBTrace/modules/orion/orion.js b/trace/FBTrace/modules/orion/orion.js
index 06ad42195a..b6280192a2 100644
--- a/trace/FBTrace/modules/orion/orion.js
+++ b/trace/FBTrace/modules/orion/orion.js
@@ -4113,7 +4113,7 @@ define("orion/textview/textView", ['orion/textview/textModel', 'orion/textview/k
 		 * Executes the action handler associated with the given name.
 		 * <p>
 		 * The application defined action takes precedence over predefined actions unless
-		 * the <code>defaultAction</code> paramater is <code>true</code>.
+		 * the <code>defaultAction</code> parameter is <code>true</code>.
 		 * </p>
 		 * <p>
 		 * If the application defined action returns <code>false</code>, the text view predefined
@@ -7020,7 +7020,7 @@ define("orion/textview/textView", ['orion/textview/textModel', 'orion/textview/k
 			if (!isWebkit) {
 				/*
 				* Feature in IE and Firefox.  It is not possible to get the style of an
-				* element if it is not layed out because one of the ancestor has
+				* element if it is not laid out because one of the ancestor has
 				* style.display = none.  This means that the view cannot be created in this
 				* situations, since no measuring can be performed.  The fix is to listen
 				* for DOMAttrModified and create or destroy the view when the style.display
@@ -11281,7 +11281,7 @@ define("examples/textview/textStyler", ['orion/textview/annotations'], function(
 		];
 
 	// Scanner constants
-	var UNKOWN = 1;
+	var UNKNOWN = 1;
 	var KEYWORD = 2;
 	var STRING = 3;
 	var SINGLELINE_COMMENT = 4;
@@ -11365,7 +11365,7 @@ define("examples/textview/textStyler", ['orion/textview/annotations'], function(
 							}
 						}
 					}
-					return UNKOWN;
+					return UNKNOWN;
 			}
 		},
 		_read: function() {
@@ -11417,7 +11417,7 @@ define("examples/textview/textStyler", ['orion/textview/annotations'], function(
 							}
 						}
 						this._unread(c);
-						return UNKOWN;
+						return UNKNOWN;
 					case 39:	// SINGLE QUOTE -> char const
 						while(true) {
 							c = this._read();
@@ -11483,7 +11483,7 @@ define("examples/textview/textStyler", ['orion/textview/annotations'], function(
 						c = this._read();
 					} while(!(c === 32 || c === 9 || c === -1));
 					this._unread(c);
-					return UNKOWN;
+					return UNKNOWN;
 			}
 		}
 	};
@@ -11520,7 +11520,7 @@ define("examples/textview/textStyler", ['orion/textview/annotations'], function(
 							return HTML_MARKUP;
 						}
 					}
-					return UNKOWN;
+					return UNKNOWN;
 				case 64: // @
 					if (this._type === DOC_COMMENT) {
 						do {
@@ -11529,7 +11529,7 @@ define("examples/textview/textStyler", ['orion/textview/annotations'], function(
 						this._unread(c);
 						return DOC_TAG;
 					}
-					return UNKOWN;
+					return UNKNOWN;
 				case 84: // T
 					if ((c = this._read()) === 79) { // O
 						if ((c = this._read()) === 68) { // D
@@ -11555,7 +11555,7 @@ define("examples/textview/textStyler", ['orion/textview/annotations'], function(
 						c = this._read();
 					} while(!(c === 32 || c === 9 || c === -1 || c === 60 || c === 64 || c === 84));
 					this._unread(c);
-					return UNKOWN;
+					return UNKNOWN;
 			}
 		}
 	};
@@ -11573,7 +11573,7 @@ define("examples/textview/textStyler", ['orion/textview/annotations'], function(
 				case 39: // SINGLE QUOTE
 				case -1:
 					this._unread(c);
-					return UNKOWN;
+					return UNKNOWN;
 			}
 		}
 	};
diff --git a/trace/FBTrace/modules/orion/source-editor.jsm b/trace/FBTrace/modules/orion/source-editor.jsm
index 7877bcb460..2306391eb3 100644
--- a/trace/FBTrace/modules/orion/source-editor.jsm
+++ b/trace/FBTrace/modules/orion/source-editor.jsm
@@ -184,7 +184,7 @@ SourceEditor.EVENTS = {
    * The TextChanged event is fired when the editor content changes. The event
    * object properties:
    *   - start - the character offset in the document where the change has
-   *   occured.
+   *   occurred.
    *   - removedCharCount - the number of characters removed from the document.
    *   - addedCharCount - the number of characters added to the document.
    */