InnoWiki is a project mainly written in JavaScript, it's free.
This is a bunch of JavaScript that renders a wiki+googledocs style editor interface. This is what you've always needed to quickly edit shared documents at the corporate.
In the current version the pages are saved into a SharePoint list, but there will be other back-ends implemented.
szabomarcell gmail Any comments, help appreciated.
innoWiki incorporates jQuery and TinyMCE, so choose any license you'd like and can. http://en.wikipedia.org/wiki/Beerware suggested.