as_admintool can be used to provide a Web interface to manage site resources. It provides a modular AJAX based user interface to execute tasks to manage different types of site resources. It comes with several plug-in modules and can be extended with additional plug-ins. It currently comes with modules for executing SQL queries and backuping up and restoring tables in a database and a file manager that allows downloading, uploading, and deleting server-side files.
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.