meSing.js : meSing.js is a JavaScript singing synthesis library that uses the Web Audio API's DSP capabilities in conjunction with the meSpeak.js speech synthesis...
enquire.js : A lightweight, pure JavaScript library for responding to CSS media queries.
stream.js : stream.js is a tiny stand-alone Javascript library that unlocks a new data structure for you: streams.
The HTML5 Shiv : The HTML5 Shiv enables use of HTML5 sectioning elements in legacy Internet Explorer and provides basic HTML5 styling for Internet Explorer 6-9, Safari...
Band.js : An interface for the Web Audio API that supports rhythms, multiple instruments, repeating sections, and complex time signatures.
Namespace.js is a small javascript script which provide namespacing utilities. It is framework independent. It also allows you to remotely include files.