MediaElement.js is an HTML5 video and audio player with Flash fallback and captions. Supports IE, Firefox, Opera, Safari, Chrome and iPhone, iPad, And
Check out mediaElementjs.com for more examples
Most HTML5 players offer one player to modern browsers and then a competely separate Flash player to older browser. This creates an inconsistent look and functionality.
Instead, MediaElement.js upgrades older browsers, using Flash to mimic the entire HTML5 Media API. Then once all the browsers have something that looks like HTML5 Media, we build a consistent player on top using just HTML and CSS.
See original blog post at johndyer.name for a full explanation of MediaElement.js