Performing tonight: Internet Explorer 6!

For the first time in my career, I'm encountering profound JavaScript performance issues in Internet Explorer while trying to manipulate elements in a very large DOM.

The situation involves pulling down a large chunk of JSON data from the server and then creating a DOM representation of that data along with all of the relevant event triggers. For reference, with a data set consisting of 50 items, this works out to somewhere in the neighborhood of a hell of a lot of DOM elements and 1500 event triggers.

The problem is rendering performance in IE, which is hovering around 15 seconds compared to half a second for Safari and a few for Firefox. Ugly, right?

So... even though I'm not finished profiling the rendering process, I thought I would share some of the information that is helping me understand how to optimize JavaScript for Internet Explorer. Enjoy.

• Quirksmode: Benchmark - W3C DOM vs. innerHTML
• IEBlog: IE+JScript Performance Recommendations
• Comet: JavaScript Performance Issues

Update:

The Comet link contained materials that were just plain wrong... so I'd like you to mentally replace it with this link from Joseph Smarr's talk on high performance JavaScript at OSCON