I was mislead by the "30-day trial" bit and happy to see this wiki page (assume it's in social text!) and this table clarifies what's going on - they provide additional support as a paid model.
I just joined my first open source project and we just started our wiki - fortunately it's brand spankin new and it might be nice to recommend this technology to help manage our project before we go too deep defining our requirements!
my mission to find an open source project that resonates with continues. Social Text is not the type of wiki I'm finding inspiring at this time. TiddlyWiki has taken the cake - it looks to be the most malleable and promising of many platforms I've evaluated. there are clearly some drawbacks of a single-page implementation but from my perspective, it gets back to basics - the days of BASIC programming for example.
stay tuned and watch our Dance Chalat TiddlyWiki continue to transform!