From http://erfurtwiki.sourceforge.net/README

Erfurtwiki provides case-insensitive Wiki links, multiple database backends, and all extended features are optional (a very exhaustive plugin interface, and over 200 ready to use plugins)

ewiki is very easy to set up, you only need a web server with PHP (4.1 or later) support. It even runs without a SQL database, but that requires additional configuration

-- MartinCleaver - 19 Dec 2004