The highlights of this release are:

* support for viewing attached office documents in the wiki
* a new User Directory
* an experimental Extension Manager
* improvements to action menus
* further improvements to the edit UI
* support for activating a special accessibility stylesheet
* more consistent use of user avatars
* an experimental xwiki/2.1 wiki syntax
* a mechanism for inserting custom links in the header
* the introduction of cancelable events
* better external search engine indexing support
* experimental CSRF protection
* experimental Cryptographic Module

See http://www.xwiki.org/xwiki/bin/Main/ReleaseNotesXWikiEnterprise25 for more details.