A fork of Darwin with the intention of making it easier to commit code and to involve the community in ways difficult with the main Apple branch. http://www.opendarwin.org/
The official Apple Darwin home page contains the current release, full source code, modification instructions, wish list, FAQ, contributors, and links. http://developer.apple.com/darwin/projects/darwin/
Goal is to provide an easy way to install various open-source software products on a Darwin, Mac OS X, FreeBSD, or Linux system. http://darwinports.opendarwin.org/
A general overview of the project to bring XFree86 (X11 server) to Darwin and Mac OS X as well as pointers to download and mirror sites. http://www.xdarwin.org/