WeHelpBUS is a Web-based help browser for Unix-like systems. It is a set of CGI scripts that enables users to browse documentation, stored in various formats, using their preferred Web browser. Current formats supported include Unix man pages, Texinfo pages, Scrollkeeper documentation catalogue (help system of GNOME and KDE), information about installed RPM packages, and C/C++ header files.
WordPress FAQ is a cool plugin for creating your FAQ section . It has a lot of parameters to set, and it will allow you set your own theme from scratch. It has a user-friendly front-end and back-end interface, allowing you to set all parameters quickly and easily. FAQs have SEO-friendly URLs.
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.