We've received quite a few requests recently for us to put the RabbitMQ code on github.
RabbitMQ is open source, and the Mercurial repositories where we work on the code are publicly accessible. But github is rapidly establishing itself as the Facebook of open-source development: It makes it easy to follow projects and participate in their development, all within a slick web-based UI.
So from today, we are mirroring our repositories to github. You can find them at http://github.com/rabbitmq. The repositories on github track our Mercurial repositories with a delay of a few minutes.
The main development of RabbitMQ will continue to take place on Mercurial. Converting our development workflow and infrastructure to git would take a lot of effort that we'd prefer to spend improving RabbitMQ. And besides, members of the team differ in their opinions about the relative merits of hg and git.
If you wish to contribute to RabbitMQ, we are happy to receive changes via github, or Mercurial hosting sites such as bitbucket, or even as old-fashioned patches!