Currently, my main contribution to free software development is my work on Debian GNU/Linux (for instance on the gnumeric package). There are always bugs to solve or to report.
I used to be somewhat involved in the development of the Little Brother network monitoring system, primarily behind the scenes, and in libpqxx whose main ideas Jeroen developed while working on Little Brother.
My Advogato page is a good sign I'm not good at keeping webpages up to date.
I've been maintainer of the Debian website, and of several Debian packages (including perl, GNU readline library, Berkeley DB library, GNU DBM library, mutt and LessTif); have assisted in the move to ELF (e.g. upstream tar configure script), and I have extended the MAKEDEV script in the base package.
Various other stuff: