A high performance implementation of the Ruby programming language. Built on the GraalVM by Oracle Labs.
Ruby Java C HTML Yacc Ragel Other



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


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.

The best way to get in touch with us is to join us in #jruby on Freenode, but you can also Tweet to @chrisgseaton, or email chris.seaton@oracle.com.

Mailing list

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

Current Status

TruffleRuby is progressing fast but is currently probably not ready for you to try running your full Ruby application on. Support for critical C extensions such as OpenSSL and Nokogiri is missing.

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 AOT, 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 today on an unmodified JDK 9 EA build, but at the moment this requires building Graal yourself and we don't recommend end-users try it. It will be supported when Java 9 is released.

How do I install gems?

TruffleRuby cannot install gems out of the box yet, however there are temporary workarounds which can be used to get it working.

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 instructions.


User documentation is in doc/user.

Contributor documentation is in doc/contributor.


TruffleRuby is copyright (c) 2013-2017 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 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.