Web Audio DAW. Use the HTML5 Web Audio API for dynamic sound synthesis. It's like jQuery for your ears.
An audio effects library for Web Audio, made by www.dinahmoe.com
A Web Audio framework for making interactive music in the browser.
alphaTab is a cross platform music notation and guitar tablature rendering library.
Library to simplify the way you create and manipulate sounds with the Web Audio API.
Navigable waveform built on Web Audio and Canvas
Media Tags Reader (ID3, MP4, FLAC)
Making life easy to create a MIDI-app on the web. Includes a library to program synesthesia into your app for memory recognition or for creating trippy effects. Convert soundfonts for Guitar, Bass, Drums, ect. into code that can be read by the browser. Supports multiple simultaneous instruments and perfect timing.
The Web Audio API, developed by the W3C Audio WG