Tiki Wiki CMS Groupware is a full-featured, Web-based, multilingual, tightly integrated, all-in-one wiki, CMS, and groupware. Tiki can be used to create all kinds of Web applications, sites, portals, knowledge bases, intranets, and extranets. Tiki offers a very large number of features "out-of-the-box". It is highly configurable and modular. All features are optional and administered via a Web-based interface. Major features include a robust wiki engine, news articles, discussion forums, newsletters, blogs, file and image galleries, bug and issue trackers, a link directory, polls/surveys and quizzes, FAQs, a banner management system, calendar, maps, mobile access, RSS feeds, a category system, tags, an advanced themeing engine (Smarty), spreadsheet, live support, shoutbox, inter-user messaging, menu generator, advanced permission system for users and groups, internal search engine, external authentication support, and more. It was formerly named TikiWiki.
RainFramework is an MVC Framework for PHP. It's easy to use and it enables teams to work better. It is installable with a simple copy/paste operation. It has a very small footprint, with just the necessary library and files. It is well documented and tested, and it allows you to create Web applications more quickly. It also supports multiple languages, has a WYSIWYG editor, and is extensible.
Elefant is a full-featured, but refreshingly simple CMS and PHP Web framework. It features an intuitive, streamlined admin interface, a tightly integrated WYSIWYG editor, dynamically embeddable content objects for building dynamic Web sites without touching code, and an extremely fast, secure, and flexible framework for add-ons and themes. The core CMS includes page editing, a blogging engine, site navigation, file and user management, automatic version control, a tool for translators and multilingual site management, and an in-browser theme/layout editor. It is also extensively documented and has a small but friendly and active developer community.