A lot of us wanted to have a place to centralize code that can be used by everyone within the Mac community. Cocoa, Carbon, Applescript, etc etc.
About
The why:
MacCode started as a discussion at C4(0). Wolf, you will appreciate that this happened in the hallway, or close enough to it. A few of us decided that it was just frustrating to find anything useful, and if we had a central location for code it'd just rock.
MacCode was started shortly after that.
The MacCode repo is a repository hosted on Google Code with a bunch of stuff in it. Notables:
Everything is 3 clause BSD.
This project also includes source code from other projects in the opensource-bsd-externals directory. You will only get the opensource-bsd-externals setup if you update the release with an svn (subversion) client.
We're aiming to put out a source release every 3 months of whatever is currently available in trunk in the subversion repo. This timeline may not always be exact though.
This distribution is an archive of a subversion (svn) working copy. Basically this means that you can update this archive at any time with what is online.
If you want the external projects checked out (projects not hosted on Google Code, but which are useful)
svn co http://maccode.googlecode.com/svn/trunk/ maccode
If you do not want the externals (they can take up a bit of space)
svn co http://maccode.googlecode.com/svn/trunk/ maccode --ignore-externals
Submit a few patches. If you have a lot of code to get checked in, file a ticket and someone will contact you directly. If you happen to know someone who works on the project, contact them directly to get your code submitted.
All code submitted must be 3 clause BSD licensed. This seems the most fair for providing sample code, while at the same time for getting credit if code is used.
Direct inquiries can be directed to Chris Forsythe http://trac.adiumx.com/wiki/the_tick .