Hmm. My understanding is that it strips out a bunch of unnecessary (correction: able to be simplified, not necessarily "unnecessary") elements and makes it easier to write leaner JavaScript. Also easier to have a browser render JavaScript.

Wittens' talk at http://acko.net/blog/jquery-oscms-presentation-slides at the OSCMS was pretty good; basically, JavaScript is not bad, but too much can be overwhelming to people.

P.S. Not always the slowest set of elements to load on a page. A fun little hack: http://www.spaceminnow.com/school - standard disclaimer -