BraneStorm is currently in very early development.

From BraneStorm

The current implementations is powered by MediaWiki (the same engine that runs Wikipedia) and Semantic MediaWiki. Other wiki systems may be considered before initial release.

BraneStorm makes intensive use of Semantic MediaWiki (SMW). SMW allows additional semantic markup into the wiki-text to improve the overall quality and consistency of the wiki. Semantic markup allows the user to specify the relationship between items in the wiki and properties of those items. It may appear to make things more complicated but it actually makes it easier for users to find more information. If you want to know more about Semantic MediaWiki check out this great 5-minute introduction.