The wiki concept was invented by Ward Cunningham in 1995. He combined simple HTML-elements in a clever way to create web pages that everybody was able to edit. He named this Wiki (Hawaiian for quick) and used it for the Portland Pattern Repository software developers community, now better known as the WikiWikiWeb or C2.
Ward Cunningham kept his more advanced source closed and therefore - and because the wiki concept was simple - a large number of programmers developed their own versions of wiki software (aka engines, clones). About 200 implementations were listed in 2005 but only about a dozen of them have momentum.
ProWiki forked from UseMod in 2001 when it became clear that we needed numerous extensions to support the special needs of our mostly German community projects: deep subpage hierarchies, user rights, page histories, better tables, more beautiful designs and literally hundreds of additional features.
Wiki became famous in 2003 because of the overwhelming success of Wikipedia. This great wiki project builds a free OpenSource online encyclopedia challenging the large commercial products like Encyclopedia Britannica or Microsoft's Encarta. So we know: a wiki can work wonders used for the right job in the hands of a great community.
The WikiPedia success attracts people like honey attracts the bees, but few wikis are encyclopedias like Wikipedia (just like few books use the technology and organisation of encyclopedias). Many people believe that using MediaWiki guarantees their success but this is a faulty and counter-productive assumption. Corporations, organizations, schools, projects, cities, individuals ... they all have different application needs to organise and structure their knowledge and collaboration. See WikiApplications.
ProWiki is different, because it can be adapted to the individual needs of wiki projects with its almost unlimited flexibility of WikiContextuality and WikiFractality. It doesn't follow a single scheme. ProWiki is a wiki but it is also a toolbox for creating wikis. It's the best wiki software for the high-quality WikiProvider.