From Seo Wiki - Search Engine Optimization and Programming Languages
FlexWiki is a wiki software engine written primarily by David Ornstein.
FlexWiki uses .NET technology and has an integrated, scripting language called WikiTalk. WikiTalk is based on the Smalltalk programming language (hence its name). It is a simple object oriented language that allows users to add dynamic behaviors to their topics.
While most Wiki software systems use a DBMS to store their content, FlexWiki started out with a textual storage system. Content was stored in text files, reducing some of the administrative overhead of maintaining a wiki site. With the release of v1.8.01653, it became possible to store FlexWiki's content in an SQL Server database, but the original textual storage system is still available and is the default storage type. It is generally not necessary to scale FlexWiki due to the advanced caching, but scaling is possible using SQL Server, providing that caching is turned off.
The engine is open source, licensed under IBM's Common Public License. Along with Windows Installer XML (WiX) and Windows Template Library (WTL), FlexWiki was the third Microsoft project to be distributed via SourceForge.net. The code was released in September 2004. The system has undergone continuous development since the initial release and has released a newer version that features a robust security model, caching and a multitude of new features.
Sites or wikis running FlexWiki