jQuery says: write less, do more
for example if you want to load a page (Test.aspx) in a div (with id="page1") you can write:
it loads test.aspx in page1 div! even you can partially load it:
the above statement loads div1's value into page1
Google has wrote it's auto-complete with jQuery!
Library. others are: YUI (Yahoo Utility Interface) widely used by yahoo (fully used in Yahoo! Mail), Dojo, MooTools, Prototype, etc
YUI is supported by Yahoo!
jQuery is supported by every one that uses it!
see domes and take a tour
in asp.net you can use Microsoft's js
library (Microsoft Ajax Library) with useful tools, but jQuery is very light and easy to load.