Using destination-over on HTML5 canvas
Example of how you can use the destination-over global composite operation on the HTML5 canvas.
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<canvas id="myCanvas" width="600" height="300"></canvas>
<script>
var ctx = document.getElementById('myCanvas').getContext('2d');
// draw a simple rectangle shape
ctx.fillStyle = "#FF0000";
ctx.fillRect(18,18,75,75);
// set the composite property shape
ctx.globalCompositeOperation = 'destination-over';
// draw a simple circle shape
ctx.fillStyle = "#0066FF";
ctx.beginPath();
ctx.arc(80,80,45,0,Math.PI*2,true);
ctx.fill();
</script>
</body>
</html>