TruffleRuby

TruffleRuby is the GraalVM high-performance implementation of the Ruby programming language.

Getting Started

TruffleRuby comes in two distributions:

• Native Standalone: This only contains TruffleRuby in the Native configuration.
• JVM Standalone: This only contains TruffleRuby in the JVM configuration. This includes support for other languages such as Java, JavaScript, Python and WebAssembly.

You can install either of those:

• Via your Ruby manager/installer (RVM, rbenv, chruby, asdf, mise, ruby-build, ruby-install).
  We recommend trying TruffleRuby dev builds which contain the latest fixes and improvements (replace VERSION by dev).

Native Standalone:

$ rbenv install truffleruby-VERSION
$ ruby-build -d truffleruby-VERSION ~/.rubies
$ asdf install ruby truffleruby-VERSION
$ mise install ruby@truffleruby-VERSION
$ ruby-install truffleruby
$ rvm install truffleruby # or truffleruby-head

JVM Standalone:

$ rbenv install truffleruby+graalvm-VERSION
$ ruby-build -d truffleruby+graalvm-VERSION ~/.rubies
$ asdf install ruby truffleruby+graalvm-VERSION
$ mise install ruby@truffleruby+graalvm-VERSION
$ ruby-install truffleruby-graalvm

• In CI with GitHub Actions, see Testing TruffleRuby in CI for more details and other CIs.

- uses: ruby/setup-ruby@v1
  with:
    ruby-version: truffleruby # or truffleruby-head or truffleruby+graalvm or truffleruby+graalvm-head

• Via Docker. For the Native Standalone there are release & nightly images. For the JVM Standalone there are no Docker images yet, but you can easily download it and take inspiration from the Native Standalone Dockerfiles.

• Manually, by following the documentation.

You can use gem and bundle to install gems, as usual.

Please report any issues you might find on GitHub.

Aim

TruffleRuby aims to:

• Run idiomatic Ruby code faster.
  • TruffleRuby is the fastest Ruby implementation for many CPU-intensive benchmarks.
• Run Ruby code and native extensions in parallel.
  • TruffleRuby does not have a global interpreter lock and runs both Ruby code and thread-safe native extensions in parallel.
• Support C extensions.
  • Many C extensions work out of the box, including database drivers.
• Add fast and low-overhead interoperability with languages like Java, JavaScript, Python and WebAssembly.
  • See the Polyglot documentation.
• Provide new tooling, such as debuggers and monitoring, that works across languages.
  • Includes a profiler, debugger, VisualVM, and more. See the Tools documentation.
• Provide all of the above while maintaining very high compatibility with the standard implementation of Ruby.

TruffleRuby Runtime Configurations

There are two main runtime configurations of TruffleRuby, Native and JVM, which have different trade-offs.

Configuration:	Native (--native, default)	JVM (--jvm)
Time to start TruffleRuby	about as fast as MRI startup	slower
Time to reach peak performance	faster	slower
Peak performance (also considering GC)	good	best
Java host interoperability	needs reflection configuration	just works

To find out which runtime configuration is being used, run ruby --version on the command line, or check the value of RUBY_DESCRIPTION or TruffleRuby.native? in Ruby code. Runtime configurations are further detailed in Deploying TruffleRuby.

System Compatibility

TruffleRuby is actively tested on the following systems:

• Oracle Linux 7, 8, 9
• Ubuntu 18.04, 20.04, 22.04 (all LTS)
• Fedora 37, 38
• Debian 10, 11, 12
• macOS 11 (Big Sur)

Architectures:

• AMD64 (aka x86_64): Supported on Linux
• AArch64 (aka arm64): Supported on Linux and on macOS

You may find that TruffleRuby will not work if you severely restrict the environment, for example, by unmounting system filesystems such as /dev/shm.

Dependencies

• make, gcc and g++ for building C and C++ extensions
• CA certificates for the openssl C extension
• zlib for the zlib C extension

Without these dependencies, many libraries including RubyGems will not work. TruffleRuby will try to print a nice error message if a dependency is missing, but this can only be done on a best effort basis.

You also need to set up a UTF-8 locale if not already done.

See the contributor workflow document if you wish to build TruffleRuby from source.

Current Status

We recommend that people trying TruffleRuby on their gems and applications get in touch with us for any help they might need.

TruffleRuby runs Rails and is compatible with many gems, including C extensions. TruffleRuby is not 100% compatible with MRI 3.4 yet. Please report any compatibility issues you might find. TruffleRuby passes around 97% of ruby/spec, more than any other alternative Ruby implementation.

Regarding performance, TruffleRuby is by far the fastest Ruby implementation on the yjit-bench benchmark suite which includes railsbench, etc. To achieve this performance TruffleRuby needs a fair amount of warmup, as other advanced JIT compilers do. If you find any performance issue, please see this guide.

Releases

TruffleRuby is released on its own schedule (based on features, important bug fixes, etc) and does not follow the GraalVM release schedule. TruffleRuby version AB.C.D aims to be compatible with CRuby A.B. For example TruffleRuby 34.0.0 aims to be compatible with CRuby 3.4. This way TruffleRuby is able to follow semantic versioning.

The last release which used GraalVM/Truffle versioning is 25.0.0.

Compatibility Table

TruffleRuby is compatible with the GraalVM versions in the following table. The Truffle version is fixed and is a dependency of the dev.truffleruby:truffleruby Maven artifact, so it cannot be chosen. It is, however, relevant when doing interop with other Truffle languages, as they must use the same version of Truffle.

TruffleRuby version	Truffle version	GraalVM versions
34.0.0	25.0.2	21.0.x, 25.0.x
33.0.0	25.0.1	21.0.x, 25.0.x
25.0.0	25.0.0	21.0.x, 25.0.x

Migration from MRI

TruffleRuby should in most cases work as a drop-in replacement for MRI, but you should read about our compatibility.

Migration from JRuby

For many use cases TruffleRuby should work as a drop-in replacement for JRuby. However, our approach to integration with Java is different to JRuby so you should read our migration guide.

Documentation

Extensive user documentation is available in doc/user.

See our source code repository and contributor documentation to contribute to TruffleRuby. In particular, see the contributor workflow document for how to build and run TruffleRuby.

Contact

The best way to get in touch with us is to join the #truffleruby channel on GraalVM Slack. You can also mention or DM @truffleruby.dev on Bluesky.

Please report security vulnerabilities via the process outlined in SECURITY.md.

Authors

The main authors of TruffleRuby can be seen on GitHub.

Security

See SECURITY.md for how to report security vulnerabilities. For known vulnerabilities in Ruby, please refer to the known-cves file.

Licence

TruffleRuby is copyright (c) 2013-2025 Oracle and/or its affiliates; 2026 TruffleRuby contributors, and is made available to you under the terms of any one of the following three licenses:

• Eclipse Public License version 2.0, or
• GNU General Public License version 2, or
• GNU Lesser General Public License version 2.1.

For further licensing information, see LICENCE, 3rd_party_licenses, and doc/legal/legal.

Attribution

TruffleRuby includes infrastructure code from JRuby (e.g. JCodings, Joni), core library code from the Rubinius project, as well as code from the standard implementation of Ruby, MRI.

Credits

We are thankful for JetBrains providing the TruffleRuby core maintainers an All Products Pack subscription. We use IntelliJ and the Ruby plugin for a great integrated experience developing TruffleRuby.