SoundManager 2 : Using HTML5 and Flash, SoundManager 2 provides reliable cross-platform audio under a single JavaScript API.
yepnope.js : A Conditional Loader For Your Polyfills!
Tracery : A story-grammar generation library for javascript. Write grammar objects, get generative stories.
Namespace.js is a small javascript script which provide namespacing utilities. It is framework independent. It also allows you to remotely include files.