Marsk Article Directory lets you build, manage, and run an article directory with ease. It comes with everything needed to let visitors submit and modify articles, supports an unlimited number of categories, and is highly customizable and completely re-brandable. It includes visitor control panels, money-making features, custom data fields, Google Maps support, many social plugins, RSS feeds, advert/banner rotators, HTML generation, article ratings and comments, mailers, and more.
Squarebase is a Web-based interface for MySQL databases. The basic idea is that it builds a database (called the "metabase") that describes the structure of the database. The information in the metabase is used to format lists and forms for browsing and editing the contents of the database.
GNU GLOBAL source code tag system is a source code tagging system which works the same way across diverse environments (Emacs, vi, less, bash, Web browser, etc.). It can locate objects in source files and move there easily. It is useful for hacking a large project containing many subdirectories, many #ifdefs, and many main() functions. It is similar to ctags or etags, but is independent of any editor.
Mychoonz is an MP3 player implemented in AJAX. It allows you to listen and organize your music within your browser, anywhere, anytime, as long as you've got an Internet connection. The idea is similar to projects such as Ampache or Mp3Act, but it focuses more on user interface rather than features.