The PressBooks open source plugin for WordPress has moved to GitHub. You can find us here: https://github.com/pressbooks.
When we launched the open source version of the PressBooks WordPress Plugin in February, we put the code up on Google Code, and were using an SVN repository. We did this for a few reasons: while we were excited about releasing the code to the public, we wanted to keep control of things early on and get into active conversations with other developers working with the code. SVN is also repo tool of choice for WordPress, so it seemed to make sense.
But of course GitHub lowers the friction for developers who want to work with open source code, and now we want to make working with PressBooks easier.
PressBooks is, we believe, the best content management system (CMS) for books — a single source system that will output your books in MOBI, EPUB, PDF, and web. Our new CSS editor means customizing outputs for PDF, EPUB/MOBI and web is now as easy as pie (if you have CSS chops). PressBooks is only going to get more powerful as more developers start improving it and customizing it for their needs.
So: Go on! Visit our GitHub page… and start forking!