When comparing MediaWiki vs Xwiki, the Slant community recommends MediaWiki for most people. In the question“What are the best multi-user wikis?” MediaWiki is ranked 2nd while Xwiki is ranked 13th. The most important reason people chose MediaWiki is:
Mediawiki is a widely used wiki engine. It is used to power Wikipedia and thus most people will be more comfortable/accustomed to using MediaWiki.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro The de facto standard
Mediawiki is a widely used wiki engine. It is used to power Wikipedia and thus most people will be more comfortable/accustomed to using MediaWiki.
Pro It has a powerful templating system
Pro Free and open source
Licensed under GPL.
Pro Version control
MediaWiki allows viewing past revisions of pages.
Pro It has a usable WYSIWYG editor
Pro Thanks to Wikipedia it is thoroughly documented
Pro Runs on any PHP server
It requires a webserver running PHP 5.2 or later of any kind.
Pro Great multilingual support
MediaWiki has full support for over 65 languages and partial support for over 300.
Pro Multiple database support
MediaWiki can store data in MySQL, PostgreSQL, Oracle and SQLite databases.
Pro Extensions
More than 600 extensions are available.
Pro Playground
You can try out XWiki in the Online Playground.
Pro Hosted
Cloud and Hosted offers are available.
Cons
Con Access control requires an extension
There is no built-in access control, but you can download an extension for ACL.