HTML5 is the latest version of HTM, HTML5 include some new features which are helpful to support for media like Audio and Video tag.
HTML5 is currently under development as the next major revision of the HTML standard.. Some rules for HTML5 were established: New features should be based on HTML, CSS, DOM, and JavaScript Reduce the need for external plugins (like Flash) Better error handling More markup to replace scripting HTML5 should be device independent The development process should be visible to the public
HTML5 is released and major browsers like Firefox, IE, Chrome ... etc support it. It enables integration of 3d graphics directly into browser using WebGL technology, so you can do some amazing things. E.g. MapsGL - smooth transitioning into street view and 3d views in google maps HTML5 browser games - Angry birds, poker, snooker and several others are already in. Many more are coming including 3D ones.