Mac OS Forge
Mac OS X includes a wide variety of open source software from FreeBSD, NetBSD, OpenBSD, the GNU Project, and many more projects each its own vibrant developer community.
Mac OS Forge is dedicated to supporting the developer community surrounding open source components specific to Mac OS X. Here you will find resources for working with the source code to popular Apple-original projects, as well as third party projects that are closely related to the Macintosh operating system.
Only select projects in Mac OS X are featured at Mac OS Forge. Look here for the complete set of open source software found in Mac OS X.
Contact Mac OS Forge
Please send any comments, suggestions, or reports of technical difficulties with Mac OS Forge itself to admin [at] macosforge.org. Issues with using one of the hosted projects should be reported directly to that project. Each project hosted at Mac OS Forge has its own contact information, so please consult their website to find their contact details.
IRC
Talk to other Mac OS Forge developers on the #macosforge channel at irc.freenode.net. Again, most projects have their own IRC channel, so you'll have better luck using those for project-specific help.
Looking for macforge.net?
MacForge.net is an index of open source projects focused on the mac. Hosted by Mac Tech Magazine, MacForge.net is not in any way affiliated with Mac OS Forge.