AV Book Library - My first open source project. A light personal use book collection manager written in PHP. Check it out!

Docuwiki - A completely awesome Wiki engine that uses flat text files, no database. Easy to install and use, I love it and I'm currently using it for my own notes/info aggregator.

eTicket - I've been trying out this support ticket system written in PHP. It seems ok, but I've had to do a lot of customizations to get menus where I want them and to fix the templates and to make it more userfriendly. I'm still not sure if I'm going to go with it. Lots of customizations means it'll be hard for me to apply any updates they release.

phpBB - A nearly perfect Forum software- I'm amazed that it's free. Has most of the features of the commercial forums out there.