Sinapse Lite is an ultra-small wiki package that uses MySQL as a backend. This powerful system allows for users to modify existing posts or create new ones, with a unique BB-code-esque system, such as using [mark="name"] to mark a location and [goto="name"]Go here[/goto] to go to the named mark, and also allows for linking to other topics by encasing them in brackets.
There is also a great revision system that compares changes to previous revisions by percent so you can tell if someone had abused the topic and replaced more than they should have. It is possible to load these revisions.
This script was developed by Scott Fitzhugh. Please visit the site to see a demo of this awesome application.
