As I got a bit interested in content management systems, I did a bit of research on free ones (well, I did a google search, to be honest).
I stumbled on Joomla! CMS which seems very good (warning: my experience with CMS's as administrator is flat zero) and is licensed under GPL.
Anyway, just wanted to mention it as an option, in case you weren't aware of its existence. I wasn't, but then again, I am a complete newbie when it comes to CMS's.