Open Source Wiki
I was recently asked to create a knowledge base system at work… knowing that there were plenty mature open source projects that would work well, I opted not to write my own and instead chose one called MoinMoin.
To be honest I did not paticullary care what language it was written in (I can program in anything). My primary concerns were stability and simplicity. My decision in selecting MoinMoin was based primarily on the fact that the people who would be responsible for adding content did not have a solid grasp on basic web technologies, would have a difficult time learning HTML, and whom I did not trust to afford the luxury of a WYSIWYG editor.
MoinMoin allows new pages to be created simply by typing in the address you want, sub pages are created as subdirectories, and content is added in plain-text format using special identifiers which are later cast to html and styles (depending on which template you use). I felt that it included an adequate amount of embedded how-to documentation for them and that the syntax should be realitively easy for them to grasp in a short time.
I did have some issues with the install… but as usual, it was my fault and I soon had it running within its own application pool on IIS. I tested the system extensively for performance in cpu and memory overhead and it runs like a champ. Time will tell if the office actually uses it though 
If you have any suggestions, questions, or experiences setting up your own Wiki I would be happy to hear from you so please comment.
For additonal help with wiki selection I recommend an article published by O’Reilly: Choosing a WIKI
