There are quite a few open source packages for wikis out there. Quite a popular choice is MediaWiki, the same software that runs Wikipedia and its sister sites, along with many other popular wikis out there.
However, today I'm going to focus on something a bit... well, lighter.
DokuWiki is a GPL 2-licensed, PHP-based wiki system. As the name suggests, it is slightly focused towards documentation, although of course ...
