OpenJDK on GitHub

Project Skara was created "to ... investigate alternative SCM and code review options for the JDK source code, including options based upon Git rather than Mercurial, and including options hosted by third parties." The OpenJDK skara-dev mailing list included a post from Robin Westberg last week that announced, "We have added some additional read-only mirrors of a few different OpenJDK project repositories to the https://github.com/openjdk group..."

The read only OpenJDK repositories on GitHub will likely be more convenient for developers wanting to take advantage of the "open source" nature of OpenJDK to take a peek at its internals. More developers are likely to be comfortable with Git than with Mercurial. The GitHub-hosted repositories make it even easier to clone a given repository or to even fork it.

As of this writing, there are currently nine public repositories hosted on the OpenJDK GitHub site:

• Current/JDK 13: openjdk/jdk
  • Mirror of https://hg.openjdk.java.net/jdk/jdk
• JDK 12 Updates: openjdk/jdk12u
  • Mirror of https://hg.openjdk.java.net/jdk-updates/jdk12u/
• Client Libraries: openjdk/client
  • Mirror of https://hg.openjdk.java.net/jdk/client/
• Project Amber: openjdk/amber
  • Mirror of https://hg.openjdk.java.net/amber/amber/
• Project Valhalla: openjdk/valhalla
  • Mirror of https://hg.openjdk.java.net/valhalla/valhalla/
• Project Panama: openjdk/panama
  • Mirror of https://hg.openjdk.java.net/panama/dev/
• Project Loom: openjdk/loom
  • Mirror of https://hg.openjdk.java.net/loom/loom/
• Project Metropolis: openjdk/metropolis
  • Mirror of https://hg.openjdk.java.net/metropolis/dev/
• Project Portola: openjdk/portola
  • Mirror of https://hg.openjdk.java.net/portola/portola/

This is not the first time the OpenJDK has been mirrored on GitHub. There are 11 repositories in "Mirror of OpenJDK repositories": jdk (2017), jdk7u-jdk (2012), jdk7u (2012), openjdk-mirror-meta (2015), corba (2015), jaxp (2015), jdk7u-langtools (2012), jdk7u-jaxws (2012), jdk7u-jaxp (2012), jdk7u-hotspot (2012), and jdk7u-corba (2012). There is also a Project-Skara/jdk that was last updated in August 2018.

Project Skara is not finished and active development of OpenJDK continues on the Mercurial-based version control system. However, the availability of important OpenJDK repositories on GitHub should make it more convenient for Java developers to analyze OpenJDK source code.