YMMV, but "TWiki is the most popular wiki used behind corporate firewall; it gets downloaded 3,000 times a month and is in use by the majority of Fortune 500 co

YMMV, but "TWiki is the most popular wiki used behind corporate firewall; it gets downloaded 3,000 times a month and is in use by the majority of Fortune 500 companies." --- It's free... http://www.wikimatrix.org/show/TWiki http://www.wikimatrix.org/show/TWiki