Most of the software here that I wrote evolved out of quick hack scripts I wrote to solve a specific problem. Accordingly, most of the software here is still a little fragile and needs more work. However, everything here works for me and possibly other people. If you're comfortable with the fact that it may be unstable unsupported nonsense, feel free to make backups and then give it a shot.
sa-harvest is a script to automate training SpamAssassin, including a custom whitelist rebuild step. The script lets you configure what mailboxes you want to train as ham and spam and then run a single command to train them all.
sa-quicktrain is a related project, allowing you to indicate -- from the client -- specific messages to be retrained as ham or spam.
Sheepdog is a system for keeping shell .files in sync across multiple unix machines (using version control, and keeping machine-specific customizations).
Phisher is an experimental SpamAssassin plugin to detect mismatches between URI anchors and text (e.g. the link says paypal.com, but it really goes to www.scammer.ru/pwn3d). It needs a lot of work (see the docs for more info), and I've only been able to test it up through SA 3.1.0, but if you'd like to test it on more recent versions please let me know how it works for you.
Bear is a personal content management system for turning large piles of text over here into consistent web pages on a server over there. It's somewhat a work in progress, but has maintained all but the blog portions of faisal.com since early 2005.
ProFontX is a version of the ProFont typeface without the ligatures that make ProFont unhappy in Mac OS X Cocoa apps (or, at least, any that I could find -- I took the version that was out there and used Fontographer to remove those ligatures. Please note that I no longer have access to Fontographer and I never had a sense of font design in the first place, so I'm not able to change this from what it is.)
The Documentation page has more information and tips on other pieces of software.