documentr is a Web-based tool for editing and presenting software documentation. It allows you to easily maintain documentation for multiple products and product branches. Edits can easily be copied between branches, with merge conflicts being handled gracefully. It uses Markdown as its markup language, along with some extensions, and has a role-based permission system.
LampCMS is a Q&A Web site with best features of StackOverflow and Quora mashed together. It integrates with Twitter, Facebook, Tumblr, and the Blogger API, and can post questions and answers to all of these APIs. It is very fast and can handle millions of monthly visitors on a single inexpensive server.
Ownyx is a lightweight MVC PHP framework for developing Web sites and Web applications. It is implemented using an object-oriented approach and offers the basics needed for building Web projects. It is easy to use and comes with clear documentation, tutorials, and examples. It also provides a developer toolbar for monitoring and debugging projects in real-time and a query builder that lets you rapidly build MySQL queries and retrieve results in data objects.