PHP: Hypertext Preprocessor

The world’s most popular open source database

Develop desktop, mobile and web applications with Java, PHP, C/C++ and more. Runs on Windows, Linux, Mac OS X and Solaris. NetBeans IDE is open-source and free.

Subversion is an open source version control system.

Trac is an enhanced wiki and issue tracking system for software development projects.

Deprecated:

An open development platform comprised of extensible frameworks, tools and runtimes for building, deploying and managing software across the lifecycle. Takes ages to do anything.