Software
LBG
LBG is a fully-working Peer-to-Peer middleware integrating advanced data transfer possibilities I helped Cyril Briquet develop. More details (and a downloadable version) on his website.
Various scripts
ulg-yp is a Perl script that can be used to query the University's staff and student database from the command line. It offers the same functionnalities as the Web interface in a perhaps more convenient (and probably more geeky) way.Note: the Web interface has since changed and I'm not willing to take the time to adapt the script. Feel free to do so if you comply with the license.
Others
Not really software, but computer-related.