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This revision made May 25, 2013 15:24, by Martijn Verburg


As of Java 7, OpenJDK is the Reference Implementation (RI) for Java. In essence, the OpenJDK is the Java we use every day! With legal and technical barriers become smaller every day, it is now more possible than ever to get involved in the language and VM that we all love.

Also, see Goals and Benefits

Who's Adopting OpenJDK?

Many individuals, JUGs and organisations, see Who Is Adopting OpenJDK

Getting Started

There are many levels, projects and smaller programmes within Adopt OpenJDK that you can join

Sign Up

You can participate in the program via:

  1. Google group: Adopt OpenJDK Google Group
  2. Mailing the Adopt OpenJDK group directly
  3. IRC: #adoptopenjdk channel on
  4. Twitter: @adoptopenjdk (follow the #adoptopenjdk hash tag on twitter)
  5. Google+ Community Google+ Community

See Adopt OpenJDK Etiquette for our community rules

Initial Steps

See Initial Steps

Join Project(s) and Event(s)

Email the Adopt OpenJDK group to signup to a project and/or an event. Some of the current projects and events include:

  • Betterrev - A new workflow for the submission of patches to OpenJDK, including a build farm / CI farm and more
  • Test Fests - Fixing existing OpenJDK tests and writing new ones
  • Lambda Tutorials - A hands on learning guide for Lambdas in Java 8
  • Javacountdown - A site to track global usage of Java in the browser.
  • Bugathons

Leading an Adopt OpenJDK effort

See Leading an Adopt OpenJDK effort

What do we work on for OpenJDK?

See What to work on for OpenJDK

Levels of contribution

This section covers the myriad ways in which you can contribute to the Adopt OpenJDK program

Starter Level

VM Build

Your own build

Evangelism, Testing & Triage

Bug fixes and small enhancements

There are some General Instructions for Small Changes which apply to most of the sub projects below.

Intermediate Level

Your First Patch

In order to get a patch ready for committing, you need to have written the patch, but there are several other things you need to do.

First off, you should be comfortable with building OpenJDK & keeping up to date with the head of the relevant repo.

You should also know (from having watched the mailing lists, or by asking on the AdoptOpenJDK mailing list) which project you should be targeting for your patch. Note that this may not necessarily be the OpenJDK 8 mainline project.

You should also have installed jtreg as that will be needed for testing your patch.

Jigsaw and OSGi

There are two parts to this. Project Jigsaw itself and project Penrose, a splinter project investigating OSGi/Jigsaw interaction

  • Jigsaw - TBA
  • Project Penrose - Lead by Neil Bartlett

jtreg, JUnit, TestNG etc

Other JDK Enhancement Proposals (JEPs)

Read Alex Blewitt's blog post for some background information on the JEP process. Some JEPs can be classed as intermediate level proposals:

  • TBA

Advanced Level

  • Finding and eliminating memory leaks. JDK provides good tools for that, 3rd-party profilers are also helpful
  • New platforms support. They can include operating systems, hardware, browsers, window managers - everything. Sometimes the fix is small, sometimes it makes sense to request a new OpenJDK project (e.g. BSD port, or PowerPC/AIX port)
  • Performance. It's a never-ending task.

Javadoc overhaul

See Javadoc for details - Lead by Ben Evans and Richard Warburton


Build and CI


  • Investigate the experimental patch by Lukas Stadler and get it up to date with OpenJDK 8 - Join co_jsrATsswDOTuni-linzDOTacDOTat for details
  • Start discussions within mlvm-dev about coroutines, their state and their suitability going forward for the JVM

Concurrency Testing

Other JDK Enhancement Proposals (JEPs)

Read Alex Blewitt's blog post for some background information on the JEP process. Some JEPs can be classed as advanced level proposals:

  • TBA

Misc Projects

Delayed Projects

  • Ux overhaul of the - This is delayed until an infrastructure move takes place.
  • Triage OpenJDK Bugs - This is delayed until the public JIRA instance is available

Talks and Presentations


See the Downloads section for this project (left hand menu).

JavaOne 2012

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