FlexWiki is an open source wiki engine written primarily by David Ornstein.
The engine is licensed under IBM's Common Public License. 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.
Along with Windows Installer XML (WiX) and Windows Template Library (WTL), FlexWiki was the third Microsoft project to be distributed via SourceForge. The code was released in September 2004.
Although 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, which, while reducing some of the administrative overhead of maintaining a wiki site, makes it difficult or impossible to scale such a system. With the release of v1.8.01653, however, it became possible to store FlexWiki's content in an SQL Server database, and thus to scale the wiki software to a server farm. The original textual storage system is still available, however, and is the default storage type.