I use Tikiwiki since June 2004 to run my own website Eidolon's Inn, which is dedicated to old computer and video games.
Since then, I have chosen Tiki for two more of my community sites:
World of M.U.L.E. - a fanpage dedicated to one of the greatest multiplayer games of all times.
Abi '97 Sophie Hedwig Gymnasium Diez - community site for the people of the final years of my school
Feel free to drop me a message anytime to discuss Tikiwiki experiences.