Best way to check for IE less than 9 in JavaScript without library

Question

What would be your fastest, shortest (best) way to detect browser which is IE and version less than 9 in JavaScript, without using jQuery or any add-on libraries?

Answer 1

I've decided to go with object detection instead.

After reading this: http://www.quirksmode.org/js/support.html and this: http://diveintohtml5.ep.io/detect.html#canvas

I'd use something like

if(!!document.createElement('canvas').getContext) alert('what is needed, supported');