Groupswiki is a simple opensource wiki that uses wysiwyg editing to lower the barrier so that more people will write to the wiki.
It uses protoedit -a richtext editor written using Prototype.js - it is compatible with:
safari firefox internet explorer. It uses ruby on rails and should work with most backend databases.
Groupswiki is agpl licensed:
If you make improvements to the source code - send them to firstname.lastname@example.org or ask me for svn-write-access.