QMachine (QM) is a web service for distributed computing. Its design relaxes the usual requirements of a distributed computer so far that it can be powered completely by web browsers – without installing anything.
TappedAudio is an audio library with an emphasis on the programming interface -- agnostic to the backend, written in highly-encapsulated C++ and using SWIG to present a unified API for C++, Python, Ruby, etc., regardless of the underlying audio platform.
Thetis is the world strongest Groupware/CMS based on Ruby on Rails. It goes beyond just a groupware to be an information-sharing webplatform integrating know-hows and ideas in the organization, with highly sophisticated functional UI by Web2.0/Ajax.