DaPortal now features a wiki module. It actually takes HTML input directly, but can also track changes (using RCS). Its code is not mature for use on this website yet (regarding permissions to commit), but you may safely expect a wiki system to appear here at some point.
This module is also a first step towards "richer" content here, as it includes an online HTML editor, which will probably be modularized and declined for news and articles. Stay tuned!