The following is a demo of the HTML5 <canvas> tag in operation:
If you cannot see this nifty demo try any of the following: 1 2 3 or 4.
Now some other nifty Canvas demos and references:
HTML5 Canvas cheat sheets – very helpful for using <canvas> scripting.
BillMalone – detailed example of using canvas to create icons with browser compatibility info.
Google IExplorerCanvas addon – gets canvas tags to work in IE8.
DivingIntoHTML5 – the excellent tutorial on the canvas tag with Halma game example.
CanvasDemos – dozens of examples, games and tutorials for using HTML5 Canvas
HTML5Demos – has 2 dozen examples of HTML5 in action including 2 canvas demos – one gets a clearer idea of the status of HTML5 regarding the 5 major browser vendors. Guess who is lagging?
Thirteen Incredible Canvas Demos – some great canvas demos plus code
Ben Joffe – again some great examples of what can be done with canvas tag
Wikipedia Canvas – concise summary of what canvas can do; but still some great links/references
Canvas Tests – A rigorous set of tests for all key canvas functions and attributes [CTL+U to see the source]