After reading Rumen Stankov's entry on telerik controls running on ie7 it reminded me of an interesting feature of Atlas. He brought up the Object detection method of deciphering what Browser is running your script.
// Good - the Object Detection Way. This is how it should be done.
if (window.attachEvent)
{
window.attachEvent('onunload', dispose);
}
// Bad. This is the most common IE client-side detection though.
if (document.all)
{
window.attachEvent('onunload', dispose);
}
What's interesting is, that if Atlas detects that you are running browsers other than IE it will include an additional file for compatibility. This .js file than adds a function to the window object called attachEvent which than wraps addEventListener.
This is great because now to attach events all you need to do is use the attachEvent function. But if you are using Atlas with your site, window.attachEvent is no longer IE only and therefore not useful as a function to be checked against for general browser detection. Something to think about, especially if you are planning on selling web controls.