I saw reference to ChucK on Prompt Criticality, a Second Life Blog. I wanted to blog it for my own reference if for no other reason. ChucK is "a new audio programming language for real-time synthesis, composition, and performance" that "presents a new time-based concurrent programming model, which supports a more precise and fundamental level of expressiveness, as well as multiple, simultaneous, dynamic control rates, a precise and straightforward concurrency, and the ability to add, remove, and modify code, on-the-fly, while the program is running, without stopping or restarting".
Sounds facinating, esp. given my recent discussion of internal vs. external DSLs w/ Neal Ford. Plus it deals w/ concurrency and is dynamic.