tony said:

>>1.9 – 2.0 versions of jQuery are major releases where IE 6,7,8 are no more supported and a lot of changed fuctionalitys is present.

jQuery 1.9 does support 6, 7, 8, but 2.0 will not.

You can read the details here: http://blog.jquery.com/2013/01/15/jquery-1-9-final-jquery-2-0-beta-migrate-final-released/

jQuery 1.9 runs on Internet Explorer 6, 7, and 8 (“oldIE”), just like previous versions. Consider it a cleaner, slimmer, modern-API upgrade from jQuery 1.8.

jQuery 2.0 will not run on oldIE. As a result of removing several layers of barnacle-encrusted code, it will be both faster and smaller than jQuery 1.9.