Chose Tettra
Although most of the tools listed above are not dedicated wikis, they do offer that feature. I like that Tettra is dedicated to the wiki space, so that allows them more time to flesh out the features for that space.
Independently Invited by TrustRadius
A de minimis incentive was given to thank the reviewer for their time. The incentive was not used to bias or drive a particular response, nor was the incentive contingent on a positive endorsement. More Info