Open Source wiki engine, written in C#/XSLT, that supports WYSIWYG editing, file attachments, searching across pages and attachments (including MS Office documents) and a flexible security model.

Commercial Windows-based implementation written in Smalltalk with limits on allowed named users, Access support, and ODBC support with more expensive versions.

A Japanese WikiClone built using dRuby, ERb, RDtool, MutexM; inspired by Tiki.

A wiki-like Web application running on .NET platforms. It is written in C#, uses ASP.NET features and stores data in SQL databases or flat XML files.

A simple, elegant wiki engine implemented in Lua. Site contains documentation for the engine.

Links to dozens of Wiki system types, in many programming languages.

Enterprise Wiki Software for download and installation. Includes support for wikis, blogs, social tagging, discussion, document management, and search.