Jmol is a Free, Open Source molecule viewer and editor. It is a collaboratively developed visualization and measurement tool for chemical scientists. Jmol is an active project, and there are new features being added to it on a daily basis. Users are encouraged to modify it to fit their needs and to contribute their changes to the project.
CodeApplet is a Java-based client-server system that is meant to be used for teaching computer programming online. It may be used with any language for which an appropriate Java class is written, and adding a new interpreter requires no recompilation of the main binaries. Users connect to different coding sessions on the server. Every session has one editor at a time, elected by privileged operators or the current editor. This editor may control a shared language interpreter and edit source files while the other users watch in realtime. Some languages also support local interpreters for personal experiments.
Dacco is a collaborative English-Catalan, Catalan-English dictionary project. It seeks to provide an up-to-date, comprehensive, bilingual dictionary that will be of benefit to learners of both languages. The dictionaries are downloadable and customizable (using XSLT) and contain audio files.
Tete allows you to select intervals, chords, or scales and play examples of the selected sounds in a random order. As each is played, it is highlighted in the list. Once you think you can tell what is playing, you can test yourself. A series of sounds will be played, again at random, and you attempt to identify what has been played. You can control how each sound is played back by changing the MIDI instrument, the octave range allowable, the root note, and whether the sounds are played ascending or descending.