MacPorts
- Aims to provide an easy way to install various open-source software products on MacOS X.
- http://www.macports.org/

HandBrake
- A GPL'd multi-platform, multithreaded DVD to MPEG-4 ripper/converter. HandBrake was originally available on the BeOS, but now has been ported over to MacOS X and to GNU/Linux.
- http://handbrake.m0k.org/

Calxalot Software
- Open source freeware for Mac OS X.
- http://calxalot.homeip.net/

Apple - Downloads - UNIX & Open Source
- The UNIX & Open Source category of Mac OS X Downloads.
- http://www.apple.com/downloads/macosx/unix_open_source/

FinkCommander
- A graphical user interface for Fink. (only for Jaguar, as of version 0.5.0)
- http://finkcommander.sourceforge.net

ONLamp
- O'Reilly's articles on LAMP: The Open Source Web Platform. Roughly defined as (but not limited to) MySQL used in conjunction with Linux, Apache, and either Perl, Python, or PHP.
- http://www.onlamp.com/

LAMP
- An ambitious project to provide a POSIX environment on Mac OS.
- http://lamp.sourceforge.net/

The Fink Project
- Unix software ported to Mac OS X, either as binaries, or from source.
- http://fink.sourceforge.net/

Mac OS X Man Pages
- Apple's collection of man pages available from the command line, but much easier to browse.
- http://developer.apple.com/documentation/Darwin/Reference/ManPages/index.html

MacDevCenter
- Mac development tutorials, opinion, and discussion from the O'Reilly Network.
- http://www.macdevcenter.com/

Red Bird Island
- Free software for the Mac of various genres.
- http://homepage.mac.com/redbird/

The Mac GNU OS X Public Archive
- Packages of all forms of Open Source Software including many Unix applications ported to or built for OS X.
- http://www.osxgnu.org