Buzz is a powerful Javascript library that allows you to easily take advantage of the new HTML5 audio element. It degrades properly on non-modern browsers.
It is a standalone library and has a very feature-rich API that can manage every feature the audio element offers.

Besides controlling the main actions like play, pause, stop or volume controls, the advanced features like looping or getting the duration of the audio are just one function away.
Buzz has many functions to get info about the audio, the capabilities of the browser (if the given media type is supported or not) and extras like fadeIn/fadeOut for the sound.
The library provides a solution to group sounds and many methods to control them which is great for handling multiple audio files at the same time.
And, a set of events like ended
, error
or volumechange
eases knowing what exactly is the status of the media and acting accordingly.
P.S. The demo of Buzz is pretty fun and make sure you check it.
Requirements: No Requirements
Compatibility: All Modern Browsers
Website: http://buzz.jaysalvat.com/
Demo: http://buzz.jaysalvat.com/demo