In 2004, some members of the W3C HTML working group (the folks responsible for crafting the Hyper Text Markup Language) decided to form a new working group with the goal of addressing real-world needs of developers. The WHATWG (Web Hypertext Application Technology Working Group) began creating the specifications of HTML 5.
Although HTML 5 has not been finalized yet it is supported by current browsers including Safari, Firefox, Opera, and IE 8. The February 20 Draft Recommendations have arrived with some interesting bits including the canvas element.
The Canvas Element represents a resolution-dependent bitmap canvas, which can be used for rendering graphs, game graphics, or other visual images on the fly.
HTML 5 promises to be backwards compatible and most developers are champing at the bit! (That's Texian for "really excited"!)