An exhaustive list of Darwin man pages.
A paper written by Wilfredo Sánchez, the then Open Source Engineering Lead at Apple, about the use of open source in commercial software such as Mac OS X Server.
A package manager for Darwin based on the Debian apt-get set of tools. 2900+ ports listed.
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.
The mascot of the Darwin OS.
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.
The official Apple Darwin home page contains the current release, full source code, modification instructions, wish list, FAQ, contributors, and links.
A paper on the design issues Apple faced when they ported the Mac OS to a semantically different Unix base (Darwin).
A Unix distribution which focuses on the porting of free software to Darwin and Mac OS X.
A helpful guide to getting and installing Darwin on an x86 system.