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.
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.
Joomla contact form builder extension is a complicated tool for making submission forms for your Joomla website. It permits you to specify parameters like colors and fonts. It can use a Google map when given an address or geographical coordinates (longitude and latitude), and the user can drag the marker to the required location.