Also, there is wiki technology. Comparing with slash and Everything, users do not own separate postings, but can edit whole page (thread). Rather radical idea, but works well. This allows cleanup after misunderstanding. Also, excellent linking to other pages (each page has meaningfull name, like DeathForDotStar).

Simple wiki you can try free is www.seedwiki.com. IMHO and AFAIK most mature/advanced wiki especially for corporate/intranet use (like for university) is TWiki, http://twiki.org, with lot of advanced features, plugins etc. Is used at university at Rome (ask for link, if interested).

pmas
To make errors is human. But to make million errors per second, you need a computer.