HTML5 Videos is a very big feature which will render Flash videos almost useless, however not every browser supports HTML5 yet, the few that do also are either development versions or beta versions.
The API in question is called “html5media” and makes use of jQuery to display the default HTML5 video player if the browser supports it, or defaults to Flowplayer if the browser does not support it.
This will ensure that your <video> tag will play in all browsers, irrespective of whether they support it or not, definitely a good way to start using HTML5 videos in your project.
Download and Learn more about html5media. You can also view the demo of the script in action by visiting this page on a HTML5 compliant browser and one which does not support it. The only downside of this is that your video needs to be encoded in either the h.264 codec (mp4) or Theora codec (ogv).