Advertise here via BSA Whilst we see, read and hear a lot about the new semantic elements in HTML5 we arguably hear far less about the application programming interfaces (APIs) that make up a large part of the specification itself. In some cases the APIs have been around and implemented for a while, but they’ve never been documented; something which HTML5 has set out to change.

See original here:
HTML5 APIs and Specification for Web Developers