This version has been in the works since October 2014. We set out to create a slimmer, faster version of jQuery (with backwards compatibility in mind). They have removed all of the old IE workarounds and taken advantage of some of the more modern web APIs where it made sense. It is a continuation of the 2.x branch, but with a few breaking changes that we felt were long overdue. While the 1.12 and 2.2 branches will continue to receive critical support patches for a time, they will not get any new features or major revisions. jQuery 3.0 is the future of jQuery. If you need IE6-8 support, you can continue to use the latest 1.12 release.
http://blog.jquery.com/2016/06/09/jquery-3-0-final-released/
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