Free Software Administration Tools For Schools?

helleman asks: "I'm interested in finding out more about open source school administration tools. Elementary and high school system administrators (often working on a volunteer basis - like myself!) are just too busy fighting fires trying to keep the school systems running (like printers, tape backups and fileservers) than to really have time to step back and evaluate/test/develop administration software properly. I could really use some advice picking some open source software either to run with (something extendable so we could code our own custom modules) OR some pointers to which software our committee should start designing our own open source school administration software with! There are many closed source options - there HAS to be some open source ones! Report Cards, Membership reports, health records, transcripts, resource administration (room bookings) and finance/contributions are a few examples of things that need to be tracked. Help!"