ChucK : Concurrent, On-the-fly Audio Programming Language
Watching a demo of ChucK, a nice open source programming language and environment developed by a group at Princeton.
From the site:
ChucK is a new audio programming language for real-time synthesis, composition, and performance, which runs on commodity operating systems. ChucK presents a new time-based concurrent programming model, which supports multiple, simultaneous, dynamic control rates, and the ability to add, remove, and modify code, on-the-fly, while the program is running, without stopping or restarting. It offers composers, researchers, and performers a powerful and flexible programming tool for building and experimenting with complex audio synthesis programs, and real-time interactive control.