XWiki is a second generation wiki engine. It features professional features like Wiki, Blog, Comments & annotations, User Rights, LDAP Authentication, PDF Export, Office Imports.
XWiki also includes an advanced form and scripting engine making it a development platform for data-based intranet applications. It has powerful features that are extensible and an highly modular architecture. The scripting engine allows to access a powerful API allowing to access the XWiki repository in read and write mode.
XWiki is used by major companies around the world and XWiki SAS (http://www.xwiki.com) provides support and services for professional usage of XWiki.
XWiki is also provided as a free hosting service for non-business/non-critical projects at http://www.myxwiki.org/. Pro hosting offerings are available at http://www.xwiki.com/en/services/hosting