A high performance implementation of the Ruby programming language. Built on the GraalVM by Oracle Labs.
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TruffleRuby logo

A high performance implementation of the Ruby programming language. Built on the GraalVM by Oracle Labs.

Getting Started

The best way to get started with TruffleRuby is via the GraalVM, which includes compatible versions of everything you need as well as TruffleRuby.


Inside the GraalVM is a bin/ruby command that runs TruffleRuby. See Using TruffleRuby with GraalVM.

We recommend that you use a Ruby version manager to use TruffleRuby.

You can use gem to install Gems as normal. TruffleRuby currently requires Bundler version 1.14.6.

You can also build TruffleRuby from source, see the Building Instructions.


TruffleRuby aims to:

  • Run idiomatic Ruby code faster
  • Run Ruby code in parallel
  • Boot Ruby applications in less time
  • Execute C extensions in a managed environment
  • Provide new tooling such as debuggers and monitoring
  • Add fast and low-overhead interoperability with languages like JavaScript, Python and R
  • All while maintaining very high compatibility with the standard implementation of Ruby


Extensive documentation is available in doc. doc/user documents how to use TruffleRuby and doc/contributor documents how to develop TruffleRuby.

System Compatibility

TruffleRuby is actively tested on these systems:

  • Oracle Linux 7
  • Ubuntu 16.04 LTS
  • Fedora 26
  • macOS 10.13

You need to install LLVM to build and run C extensions and zlib and libssl for openssl. You may also need to set up a UTF-8 locale.

Current Status

TruffleRuby is progressing fast but is currently probably not ready for you to try running your full Ruby application on.

TruffleRuby is ready for experimentation and curious end-users to try on their gems and smaller applications.

Common questions about the status of TruffleRuby

Do you run Rails?

We do run Rails, and pass the majority of the Rails test suite. But we are missing support for OpenSSL, Nokogiri, and ActiveRecord database drivers which makes it not practical to run real Rails applications at the moment.

What is happening with native, startup time, and the SubstrateVM?

You don't need a JVM to run TruffleRuby. With the SubstrateVM it is possible to produce a single, statically linked native binary executable version of TruffleRuby, which doesn't need any JVM to run.

This SubstrateVM version of TruffleRuby has startup performance and memory footprint more similar to MRI than TruffleRuby on the JVM or JRuby. There are instructions for using it as part of GraalVM.

Can TruffleRuby run on a standard JVM?

It is possible to run on an unmodified JDK 9 but you will have to build Graal yourself and we recommend using GraalVM instead.


The best way to get in touch with us is to join us in https://gitter.im/graalvm/truffleruby, but you can also Tweet to @TruffleRuby, or email chris.seaton@oracle.com.

Mailing list

Announcements about GraalVM, including TruffleRuby, are made on the graal-dev mailing list.


The main authors of TruffleRuby in order of joining the project are:

  • Chris Seaton
  • Benoit Daloze
  • Kevin Menard
  • Petr Chalupa
  • Brandon Fish
  • Duncan MacGregor


  • Thomas Würthinger
  • Matthias Grimmer
  • Josef Haider
  • Fabio Niephaus
  • Matthias Springer
  • Lucas Allan Amorim
  • Aditya Bhardwaj

Collaborations with:

And others.


See the security documentation.


TruffleRuby is copyright (c) 2013-2018 Oracle and/or its affiliates, and is made available to you under the terms of three licenses:

  • Eclipse Public License version 1.0
  • GNU General Public License version 2
  • GNU Lesser General Public License version 2.1

TruffleRuby contains additional code not always covered by these licences, and with copyright owned by other people. See doc/legal/legal.md for full documentation.


TruffleRuby is a fork of JRuby, combining it with code from the Rubinius project, and also containing code from the standard implementation of Ruby, MRI.