dancer.js : dancer.js is a high-level audio API, usable with both Mozilla's Audio Data API and Webkit's Web Audio API with flash fallback, designed to make sweet ...
Band.js : An interface for the Web Audio API that supports rhythms, multiple instruments, repeating sections, and complex time signatures.
howler.js : howler.js is an audio library for the modern web. It defaults to Web Audio API and falls back to HTML5 Audio.
Wave.js : Audio visualizer library for javascript. Create dynamic animations that react to an audio file or audio stream.
Tracery : A story-grammar generation library for javascript. Write grammar objects, get generative stories.
This is a javascript library (with frontend) for sound effect generation.