Ikiwiki is a wiki compiler. It converts wiki pages into HTML pages suitable for publishing on a website. Ikiwiki stores pages and history in a revision control system such as Subversion or Git. There are many other features, including support for blogging and podcasting, as well as a large array of plugins.
Alternatively, think of ikiwiki as a particularly flexible static site generator with some dynamic features.
Setup has a tutorial for setting up ikiwiki, or you can read the man page. There are some examples of things you can do with ikiwiki, and some tips. Basic documentation for ikiwiki plugins and syntax is provided here. The forum is open for discussions.
All wikis are supposed to have a sandbox, so this one does too.
This site generally runs the latest release of ikiwiki; currently, it runs ikiwiki 3.20140228.