Web Forms : Web Forms 2.0 Cross-Browser Implementation
Parsley.js : Javascript forms validation.
Powerful, UX aware & Dead simple.
SoundManager 2 : Using HTML5 and Flash, SoundManager 2 provides reliable cross-platform audio under a single JavaScript API.
Band.js : An interface for the Web Audio API that supports rhythms, multiple instruments, repeating sections, and complex time signatures.
Hyperform : Hyperform is a complete implementation of the HTML 5 form validation API in Javascript. It replaces or polyfills the browser’s native methods and ease...
HTML5Forms.js is a JavaScript polyfill that implements a subset of the HTML5
Forms module in all browsers. The script will only add support for the
different parts of the module when there doesn't exist a native
implementation.