Roadkill .NET is a lightweight but powerful Wiki platform built on the following foundations:
Roadkill is licensed under the MS-PL license which means it's free to use commercially or privately, but requires you to retain the copyright, trademark and attribution if you intend to distribute it (typically for commercial gain).
Try the demo site
This site will house downloads, plugins and documentation for Roadkill shortly.
Image by visentico (ShareAlike CC)