HTML5 supports the <video> tag - and most (decent) browsers support the open source and free ogg theora codec. If you're using a browser that supports these (Firefox, newer Opera and possbily Chrome), you should be able to see this simple demo.

Browsers support a default set of "controls" that have play/pause/scrobbing/mute/volume, but are not skinnable. This demo is just to showcase some of the events, properties and methods available to use natively embedded video using standard javascript.

Videos are rips from youtube (sorry for the bad quality - it's not the codec, I promise) of three popular "open source movies".

Icons courtesy of Deleket.com.