mfw allows multiple firewall configurations to be managed from the commandline on Mac OS X. Multiple firewall modes (and easy means of selecting between them) are useful on laptops, where one may want a default paranoid firewall, a mode for network scanning with nmap, modes for various networked games, or to run a software Network Address Translation (NAT) wireless base station.
Glypha III is a Mac OS X port of the classic arcade game in which you are placed inside an Egyptian temple and forced to do battle with Sphinxes in order to gain the honour of a place in the High Scores. The game is based on Joust and features sound and animated graphics from the original Mac version.
blurt is Web publishing ("blogging") software. Unlike most blogging software, it does not provide you with a fancy back office, heavy duty database backends, and massive user management systems. Instead, you upload documents ("posts") in simple text format (.txt) to a directory on your Web server. blurt will figure out the rest.
Brace is a dialect of C that looks like Python. It has coroutines, hygenic macros, header generation, and libraries with graphics and sound. It is meant to be good for beginners, kids, and experts. Brace is translated to C, then compiled, with #! support and cached executables. It is fairly portable, and runs on GNU/Linux, Unix, and Windows with MinGW. It should also run on Mac OS X. It comes with a lot of demo programs, many with animated graphics.