Work on HTML5 began in 2004 through a collaborative effort between the W3C and WHATWG. It introduces new semantic elements, supports embedded video and audio, introduces the canvas element for drawing, and improves forms. While the specification is still in development, browser support is increasing and many of the new features can be used now to have cleaner code and stay ahead of changes. However, lack of support in some browsers and the evolving specification mean disadvantages include things may change and not work everywhere.