XWiki is a WikiWiki clone written in Java that supports many popular features of other Wikis like the Wiki syntax, version control, attachments, security, and searching, but also many advanced features like templates, database and dynamic development using scripting languages (Velocity, Groovy, Ruby, Python, PHP, and more), an extension system and skinability, J2EE scalability, an XML/RPC remote API, statistics, RSS feeds, PDF exporting, WYSIWYG editing, an Office viewer and importer, and a lot more.
The second milestone of the 5.2 release comes with multiwiki support enabled by default. Users are able to create new wikis without the need to install additional extensions. This is possible because the Workspace Application has been integrated into XWiki Enterprise. Besides this, the new release brings a Solr-based live search (to replace the one based on Lucene) and the ability to track active XWiki installs. Developers will be interested by the new WikiStream framework. As with other releases, this one has a lot of bug fixes (92) and improvements (33) which make it worth trying.
URL: XWiki - Open Source Wiki and Content-Oriented Application Platform (Main.WebHome) - XWiki.org