I just started using Tiki.
My presence as a developer is motivated by two things:
1. Tiki has an amazing feature set.
2. My users require being able to have spaces and ' and . in page names and user names and such.
Since ', in particular, still hits a lot of errors until all the queries are moved over, well, it's my second day using Tiki, and I just submitted my 4th patch. 8)
Our Tiki, such as it is, is at http://www.lojban.org/tiki/
I can be reached at firstname.lastname@example.org