Re: Comparing Social Intranet Software...I need help ASAP!
I hope you found http://www.wikimatrix.org/ already.
ThoughtFarmer appears to be pretty tightly tied to the Windows platform, which I would consider a big negative, but I guess that depends on your userbase. Anyway, go down the wikimatrix features lists for these and you can easily see what each has and doesn't have.
-- Gary