Canvas is the method of generating fast, dynamic graphics using JavaScript.

Browser Support

Canvas is already supported by all major browser so it should be really easy to get it working cross browser.

Code Example

You can use Canvas like this:

var c = document.getElementById("myCanvas");
var ctx = c.getContext("2d");
ctx.fillStyle = "#FF0000";
ctx.fillRect(0,0,150,75);

More Information

More information can be found here.