JRuby 10.1: Experimenting and Evolving

The JRuby community is pleased to announce the release of JRuby 10.1.0.0.

Homepage: https://www.jruby.org/
Download: https://www.jruby.org/download

JRuby 10.1.0.x targets Ruby 4.0 compatibility.

Thank you to our contributors this release, you help keep JRuby moving forward!

JRuby 10.1: Experimenting and Evolving

JRuby 10.1.0.0 is our first major release since catching up with Ruby compatibility. We have used this opportunity to explore many experimental optimizations and improvements we have been chasing for many years. Ruby 4.0 compatibility is largely complete, but there will be additional features added in update releases. We also plan to continue with large scale experiments in subsequent updates, and recommend production users continue to use JRuby 10.0 while we work toward stabilization of the 10.1 series.

Here's an overview of the major enhancments already in JRuby 10.1.0.0 and others planned for update releases in the coming months.

Reduced Object Size

In JRuby 10.1 all objects have been reduced in size by 8 bytes, bringing the base object size down from 32 bytes to 24 bytes. This translates into smaller objects across the system, reduced GC load, higher allocation throughput, and better cache locality.

On JVM versions that support Compact Object Headers (JEP 450: "Project Lilliput") the base object size can be further reduced to 16 bytes, 40% smaller than objects in the standard Ruby implememtation.

Evolving Strings, Arrays, and Hashes

During the upcoming JRuby 10.1 update releases, we plan to introduce new versions of String, Array, and Hash that are optimized for memory compactness, concurrency, or integration with other JVM languages. To support these features, we have made the internal implementations RubyArray and RubyHash into abstract classes and deprecated the direct constructors for RubyString. Please test your JRuby extension code and make sure it does not call abstract or deprecated constructors.

Smaller Numeric Representations

JRuby's internal class for representing 64-bit signed Integer values, RubyFixnum, has been split into two versions: LongFixnum and ShortFixnum. Combined with the reduced size of objects overall, this reduces the size of these long and short-ranged Integer objects from 40 bytes to 32 bytes or 24 bytes (24 bytes or 16 bytes if using Compact Object Headers). The size of Float objects have similarly been reduced from 40 bytes to 32 bytes. These size reductions help improve the performance of numeric algorithms and reduce impact to the heap and GC of boxing numeric values.

Cross-platform Prism Parser

JRuby 10.1 ships with support for the Prism Ruby parser, packaged as a set of pre-optimized native builds (for Windows, Linux, and MacOS on x86_64 or arm64) or as a WASM build on other platforms. We're still working out a few remaining features, but we encourage experimenters to enable it by passing -Xparser.prism to JRuby. We plan to make this the default parser once the remaining issues are solved.

Direct Argument Passing

We have also laid the groundwork to start passing all forms of method arguments on the call stack, avoiding boxed collections for most optional and keyword arguments. In upcoming JRuby 10.1 releases, we will begin to connect these call paths up for both pure-Ruby and native (Java) method targets, eliminating box allocation and drastically improving the peformance of such forms. Watch this space for rapid improvements.

New Policy for EOL and LTS Releases

With the release of JRuby 10.1, we are moving JRuby 9.4 into a "soft" EOL status. This means we will no longer be doing regular OSS release updates of JRuby 9.4, but users may get in contact with us to sponsor continued support. JRuby 10.0 will be our stable LTS release until April 2028 and we recommend all users upgrade or get in contact with us for assistance. JRuby 10.1 will be our "tip" release line, with many exciting optimizations and enhancements due to land over the next several months.

Going forward, we will provide a new LTS baseline release every two years, starting in spring of 2027, and alternating years will be considered as edge or development versions without LTS guarantees. This will allow us a free hand to keep bringing you more experimental features while still providing a stable baseline for more conservative users.

Try JRuby Today!

Users can install JRuby 10.1 through the usual means, and we encourage you to give it a try and let us know how it handles your applications and libraries. We have much more planned for the 10.1 updates and hope to move fast and push the edges of what's possible with Ruby on the JVM.

59 Issues and PRs resolved for 10.1.0.0

#8716 dup a lot
#8747 Launcher script chokes on GraalVM release file
#9055 Array experiments
#9066 Move Set to a core class [Ruby 4.0]
#9069 Implement Ruby 4.0 support
#9074 Avoid array allocation for *nil, by not calling nil.to_a
#9075 Selective inspect of instance variables
#9077 No numbered parameters in Binding#local_variables
#9078 Add Math.{expm1,log1p}
#9079 Align IO.select timeout logic with CRuby
#9083 Implement missing raise features
#9085 Specialize Fixnum
#9090 Reduce the size of the varTableStamp
#9091 Shrink varTableStamp
#9095 Eliminate global flags
#9096 Cache object ID and hash in low-count immediate values
#9102 Add a fast path for hashing numerics and immediates
#9113 Performance regression in RubyHash for large hashes (~8-10x slower than JRuby 1.7)
#9119 Implement fast-path builtin method flags
#9123 Fast builtin validation experiment
#9124 Reduce load factor for Hash from 5 to 2
#9136 Marshal.load 2.9x regression vs JRuby 1.7
#9143 Cache both hash forms for FString
#9148 Allow logical ops to begin on beginning of next line
#9154 Mask internal Ruby backtrace elements like native masking
#9156 Small marshal fixes
#9174 Add complete thread-local builtin tracking system (Issues #9116, #9119)
#9180 [Implement implicit param logic for Binding][#9180]
#9181 [Fix Data subclasses with ivars][#9181]
#9202 [A Data object should be frozen even if it has no members][#9202]
#9209 [Add ruby_bug for spec of Data with no members being frozen][#9209]
#9210 [Remove Process::Status#& and Process::Status#>>][#9210]
#9233 [Load boot scripts from classloader URI][#9233]
#9235 [Use capitalized Class and Module for frozen errors][#9235]
#9236 [Properly handle keywords in {Kernel|Thread|Fiber}#raise][#9236]
#9238 [Cloned class's singleton class has too many classes in hierarchy][#9238]
#9239 [Fix for cloned class singleton class has too many ancestors][#9239]
#9250 [Update Unicode to Version 17.0.0 and Emoji Version 17.0][#9250]
#9262 [Abstract RubyHash][#9262]
#9263 [Implicit param fixes for proc and binding][#9263]
#9266 [Endless method with modifier method does not parse][#9266]
#9273 [Cleanup recursion guards][#9273]
#9277 [Use live counts for event hook stats][#9277]
#9279 [Move fiddle back to default temporarily for resolv][#9279]
#9286 [Proposing RISC-V architecture support][#9286]
#9287 [Add riscv64 platform support][#9287]
#9298 [Ensure we have a classloader to boot from][#9298]
#9299 [Delete methods deprecated prior to JRuby 9.4.0.0][#9299]
#9300 [Replace now-deprecated wait_timeout][#9300]
#9313 [Time being returned as ASCII-8BIT encoding in JRuby 10][#9313]
#9318 [Process.detach raises ArrayIndexOutOfBoundsException if called from a thread that is not the main thread][#9318]
#9325 [[fix] NullPointerException from closed IO][#9325]
#9362 [Allow endless methods to be an argument to methods like visibity][#9362]
#9365 [Marshal load perf][#9365]
#9371 [Deprecate all public RubyString constructors][#9371]
#9374 [Integrate WASM-based Prism parser into standard build][#9374]
#9383 [Disable IntFixnum][#9383]
#9384 [Set.new(a_set) throws LocalJumpError][#9384]
#9385 [Fixes #9384. Set.new(a_set) throws LocalJumpError][#9385]

The JRuby community is pleased to announce the release of JRuby 10.0.5.0.

Homepage: https://www.jruby.org/
Download: https://www.jruby.org/download

JRuby 10.0.5.x targets Ruby 3.4 compatibility.

Thank you to our contributors this release, you help keep JRuby moving forward! @evaniainbrooks, @kares, @chadlwilson, #jimtng

Compatibility

Fixed: Two bugs in the JIT compiler that broke certain super calls and defined_method yields. (#8944, #8946, #9310, #9349)
Fixed: Fiber#raise left the fiber in an resumable state by not correctly transfering control. (#9297, #9356)
Fixed: Connecting a socket using nonblocking operations failed to complete the establishment of the connection. This affected Redis users, among other cases. (#9304, #9305)
Fixed: Process#detach raised a NullPointerException if called from a non-main thread. (#9314, #9311)

JVM Integration

Java 26 is officially supported. (#9332)

Platform Integration

New platform support: The native library backend for JRuby, JNR, has been updated to include support for the RISCv64 architecture.
Fixed on Windows: File#flock used unsupported native operations on Windows, causing it to raise errors. This affected the "logger" library, among other cases. (#9347, #9348)
Fixed on Windows: IO#popen failed to pass keyword arguments if also given a leading environment hash. (#9351, #9352)

Stability

Fixed: Several memory leaks that affected users running multiple JRuby instances in a single process. (#9070, #9092, #9187, #9359)

43 Issues and PRs resolved for 10.0.5.0

The JRuby community is pleased to announce the release of JRuby 10.0.4.0.

Homepage: https://www.jruby.org/
Download: https://www.jruby.org/download

JRuby 10.0.4.x targets Ruby 3.4 compatibility.

Thank you to our contributors this release, you help keep JRuby moving forward! @evaniainbrooks, @katafrakt, @mrnoname1000

Standard Library

The syslog library moves to bundled gems. (#9198)
The unicode_normalize library is now thread-safely loaded as an internal library (#9231, #9232)

43 Issues and PRs resolved for 10.0.4.0

@mrnoname1000

layout: post
title: JRuby 10.0.3.0 Released

The JRuby community is pleased to announce the release of JRuby 10.0.3.0.

Homepage: https://www.jruby.org/
Download: https://www.jruby.org/download

JRuby 10.0.3.x targets Ruby 3.4 compatibility.

Thank you to our contributors this release, you help keep JRuby moving forward! @mrnoname1000, @ngr-ilmarh, @Earlopain, @philr, @jotamartos, @kares, @aleksandrs-ledovskis, @trinistr, @katafrakt, @chadlwilson, @khasinski, @evaniainbrooks

Compatibility

JRuby now reports RbConfig::CONFIG['arch'] without a version number, as universal-java. This allows using different JDK versions without triggering RubyGems missing extension warnings for installed gems. The host Java version is still available as RbConfig::CONFIG['arch_version']. [#9107]

Standard Library

The non-gem standard library is upgraded to Ruby 3.4.5 #8967
rexml is updated to 3.4.4 to address CVE-2025-58767. #9011
syslog is moved to a default gem at version 0.4.0. The syslog gem now includes JRuby support. [#9109], ruby/syslog#1
strscan is updated to 3.1.7. [#9159]

Documentation

Ruby ri documentation for core and standard library are now included in the release distribution. #9049, #9052

All Issues/PRs

#8707 WARNING: A terminally deprecated method in sun.misc.Unsafe has been called
#8727 Cannot install latest rubocop
#8730 Launcher: Defensive fixes
#8758 Require is not working for .class file if the class is inside a module since 9.3.0
#8810 Possible fix for 8809
#8923 NameError for autoloaded constant with private_constant
#8934 JRuby under Java 22+ always thinks it's running under a TTY
#8940 Verify to_s is string or fall back on anyToString
#8947 New check for System.console tty on JDK 22+
#8955 Range#count always returns size for Integer bounds
#8956 Handle argument or block passed to Range#count
#8958 Concurrent requires can lead to StringIndexOutOfBoundsException
#8960 Fix index -1 error while searching for feature path
#8962 Upgrade polyglot and remove openssl lib hack
#8967 Update stdlib to 3.4.5 and clean up old files
#8975 Use RuboCop to clean up poms (10.x)
#8976 Regression in keyword argument matching in JRuby v10.0.1.0
#8978 Additional fixes for scheme-based globbing
#8984 glob refactoring
#8985 Fix language spec where error string changed
#8987 InvokeDynamicSupport.findVirtual fails with IllegalAccessException: symbolic reference class is not accessible
#8989 Explicitly request access before Lookup.find*
#8994 autoload + private_constant do not play well together
#8995 private_constant should just update existing autoload
#8996 Avoid binding unreadable modules' classes
#8998 Time#localtime incorrectly treats zero offset as UTC (regression in v10.0.2.0)
#9006 Consider .class a source extension during search
#9007 Handle warn(foo, uplevel: nil)
#9009 Encoding a string with undefined chars fails with NoMethodError
#9010 Fix "+00:00" and 0 being treated as UTC by Time#localtime and Time.at
#9011 Update rexml gem to solve CVE-2025-58767
#9016 [fix] regression calling static hash() method on Java proxy
#9017 can not use Java class with static hash() method
#9018 Parser does not convert newlines reading \r\n on Windows
#9019 We need to remove \r from heredoc strings
#9021 Retire safe double processing utilities
#9024 Move all main classes to org.jruby.main package
#9027 Add "since" to bare Deprecated annotations
#9035 IO#read does not clear code-range for buffer argument
#9036 fix: clear code-range when re-using a string buffer
#9038 Add opens and native access to all jar manifests
#9039 Update all jnr dependencies
#9041 Migrate .java-version contents to .jruby.release
#9049 ri docs are not available for core
#9050 Marshal fails to load an encoding with an encoding ivar
#9051 Ignore encoding when unmarshaling an Encoding
#9052 Download and include in dist CRuby's rdoc data
#9058 Implement efficient unshifting
#9059 [Reserve extra space before elements when unshifting][#9059]
#9063 [Hash's compare_by_identity state does not marshal][#9063]
#9065 [Preserve compare_by_identity for marshaled Hash][#9065]
#9068 [Windows CI spec runs][#9068]
#9073 [fix: Permit overriding of JSA file location using ENV variable][#9073]
#9084 [object_id improvements][#9084]
#9094 [Implement GC.config [Ruby 3.4]][#9094]
#9097 [Update jruby-openssl to v0.15.5 to resolve BouncyCastle 1.79 vulnerability (sonatype-2025-001911).][#9097]
#9098 [Fix CoverageData.mergeLines when coverage increases][#9098]
#9101 [Cached fixnums for immediate values][#9101]
#9103 [Update jruby-openssl to 0.15.5][#9103]
#9106 [Use smaller default size for many collections][#9106]
#9107 [Separate Java version out of rbconfig 'arch'][#9107]
#9108 [Tidy up default gems][#9108]
#9109 [Switch to syslog gem][#9109]
#9110 [Calling inspect on proc resets line in source_location][#9110]
#9112 [Prevent modifying state in RubyProc][#9112]
#9117 [Add file path to error message when unlinking non-existing file][#9117]
#9122 [Unexpected jruby.sh error messages on Windows][#9122]
#9127 [fix(launcher): correct parsing of java release files under Bash/msys2 etc on Windows][#9127]
#9138 [Copy Data type's var table manager with new realClass][#9138]
#9141 [refactorings and cleanup motivated by error-prone][#9141]
#9142 [Change GC's methods from module_function to metaclass methods][#9142]
#9145 [Never trust external content for FString][#9145]
#9152 [Marshal.dump corruption for large Array structures][#9152]
#9157 [bump included gems][#9157]
#9158 [Use same key match for containsKey][#9158]
#9159 [Update strscan to 3.1.7][#9159]
#9182 [Fix NoMethodError when encoding with invalid: :replace option][#9182]
#9188 [Different arguments for each.map vs each and map alone (10.0)][#9188]
#9189 [Fixes #8952. Nest it should be different its][#9189]
#9190 [Backport implicit local variable fixes from 10.1][#9190]
#9191 [Fixes #8952. Nested 'it' behavior broken][#9191]
#9192 [Stab at Fixing #8976][#9192]
#9194 [BigDecimal#+, #-, #add, #sub always try to cast result of coercion to RubyBigDecimal][#9194]
#9196 [require "bigdecimal" does not install BigDecimal() if it was called previously][#9196]
#9199 [Output formatting differences between jRuby 10.0.0.1 and Ruby 3.4 when converting Float to JSON][#9199]
#9200 [Extract float formatting into a static method to use with to_json][#9200]
#9203 [Invalidate method caches from generated populators][#9203]
#9204 [Fix BigDecimal#+, #-, #add, #sub failing when coercing doesn't return a BigDecimal][#9204]
#9205 [Fix encoding fallback error handling and error message formatting][#9205]

The JRuby community is pleased to announce the release of JRuby 9.4.14.0.

Homepage: https://www.jruby.org/
Download: https://www.jruby.org/download

JRuby 9.4.14.x targets Ruby 3.1 compatibility.

Thank you to our contributors this release, you help keep JRuby moving forward! @matthias-fratz-bsz, @ikaronen-relex, @ylecuyer

Compatibility

Ruby version is now 3.1.7. (#8966)

Libraries

strscan is updated to 3.1.5. (#8897)
cgi is updated to 0.3.7 to resolve CVE-2025-27220 and CVE-2025-27219 (#8954, #8966)
uri is updated to 0.12.4. (#8966)
net-smtp is updated to 0.3.1.1. (#8966)
rss is updated to 0.3.1. (#8966)
Non-gem stdlib has been updated to Ruby 3.1.7 sources. (#8966)

Build

jruby-maven-plugins is updated to 3.0.6 to resolve issues with garbled gem poms. (#8898)
The stdlib build scripts have been modified to work with latest polyglot-ruby. (#8634, #8963)

Usability

bin/ruby and bin/ruby.bat are now shipped in the distribution, to make installation simpler. (#8875)

29 Issues and PRs resolved for 9.4.14.0

The JRuby community is pleased to announce the release of JRuby 10.0.2.0.

Homepage: https://www.jruby.org/
Download: https://www.jruby.org/download

JRuby 10.0.2.x targets Ruby 3.4 compatibility.

Thank you to our contributors this release, you help keep JRuby moving forward!

7 Issues and PRs resolved for 10.0.2.0

The JRuby community is pleased to announce the release of JRuby 10.0.1.0.

Homepage: https://www.jruby.org/
Download: https://www.jruby.org/download

JRuby 10.0.1.x targets Ruby 3.4 compatibility.

Thank you to our contributors this release, you help keep JRuby moving forward!

Compatibility

Zeitwerk is now fully supported. (#6781, #8852, #8853, #8863, #8777)

Libraries

The net-imap library is updated from 0.5.4 to 0.5.8 (#8826, #8828)

62 Issues and PRs resolved for 10.0.1.0

The JRuby community is pleased to announce the release of JRuby 9.4.13.0.

Homepage: https://www.jruby.org/
Download: https://www.jruby.org/download

JRuby 9.4.13.x targets Ruby 3.1 compatibility.

Thank you to our contributors this release, you help keep JRuby moving forward!

Stability

Fixed a slow memory leak in subclass management. (#8842, #8844)
Fixed a potential deadlock during multi-threaded boot and concurrent JIT compilation. (#8845, #8849)

Usability

Backported JRuby .sh launcher features from JRuby 10, including AppCDS flags for improved startup time. (#8565, #8625, #8626, #8652, #8653, #8656, #8754)

56 Issues and PRs resolved for 9.4.13.0

The JRuby community is pleased to announce the release of JRuby 10.0.0.1.

Homepage: https://www.jruby.org/
Download: https://www.jruby.org/download

We've jumped to Ruby 3.4 compatibility and Java 21 minimum to bring you the best Ruby on JVM experience possible. We are confident this is the most compatible and stable major release we've ever had.

Security

jruby-openssl has been updated to 0.15.4, which re-enables hostname verification by default. This addresses CVE-2025-46551 and GHSA-72qj-48g4-5xgx.

The JRuby community is pleased to announce the release of JRuby 9.4.12.1.

Homepage: https://www.jruby.org/
Download: https://www.jruby.org/download

JRuby 9.4.12.x targets Ruby 3.1 compatibility.

Security

jruby-openssl has been updated to 0.15.4, which re-enables hostname verification by default. This addresses CVE-2025-46551 and GHSA-72qj-48g4-5xgx.

Uh oh!

Releases: jruby/jruby

JRuby 10.1.0.0

JRuby 10.1: Experimenting and Evolving

Reduced Object Size

Evolving Strings, Arrays, and Hashes

Smaller Numeric Representations

Cross-platform Prism Parser

Direct Argument Passing

New Policy for EOL and LTS Releases

Try JRuby Today!

59 Issues and PRs resolved for 10.1.0.0

Uh oh!

JRuby 10.0.5.0

Compatibility

JVM Integration

Platform Integration

Stability

43 Issues and PRs resolved for 10.0.5.0

Uh oh!

JRuby 10.0.4.0

Standard Library

43 Issues and PRs resolved for 10.0.4.0

Uh oh!

JRuby 10.0.3.0

layout: post title: JRuby 10.0.3.0 Released

Compatibility

Standard Library

Documentation

All Issues/PRs

Contributors

Uh oh!

JRuby 9.4.14.0 Released

Compatibility

Libraries

Build

Usability

29 Issues and PRs resolved for 9.4.14.0

Uh oh!

JRuby 10.0.2.0

7 Issues and PRs resolved for 10.0.2.0

Uh oh!

JRuby 10.0.1.0

Compatibility

Libraries

62 Issues and PRs resolved for 10.0.1.0

Uh oh!

JRuby 9.4.13.0

Stability

Usability

56 Issues and PRs resolved for 9.4.13.0

Uh oh!

JRuby 10.0.0.1 Released

Security

Uh oh!

JRuby 9.4.12.1 Released

Security

Uh oh!

layout: post
title: JRuby 10.0.3.0 Released