The versions of IE that jQuery 2.0 will not support include 6, 7 and 8. You can check the full blog entry, which provides details of the planned development path. But don't panic; just because jQuery 2.0 won't support those old browsers doesn't mean that the library will stop supporting them altogether.
First, keep in mind that the current version of jQuery is 1.8. jQuery 2.0 isn't scheduled to come out until early 2013. A little before jQuery 2.0, the developers will come out with jQuery 1.9. In this version of the library, “We'll remove many of the interfaces already deprecated in version 1.8; some of them will be available as plugins or alternative APIs supported by the jQuery project. IE 6/7/8 will be supported as today.”
Going forward, jQuery will come in two supported flavors, jQuery 1.9.x and jQuery 2.0. jQuery 1.9.x will continue to support the older IE browsers. Jquery 2.0, on the other hand, “will support the same APIs as jQuery 1.9 does, but removes support for IE 6/7/8 oddities such as borked event model, IE7 'attroperties,' HTML5 shims, etc.”
Why is the jQuery team doing this? The need to support “oldIE,” as the developers refer to it, has “been a thorn in the side of web developers for a decade.” Creating a version of jQuery that doesn't support those old browsers gives developers more room to innovate. At the same time, creating and maintaining a version of jQuery that DOES continue to support “oldIE” lets jQueryy developers serve the more than thirty percent of website visitors, on average, that use the older technology.
According to a follow-up post, the jQuery core team will continue to support jQuery 1.9 “as long as oldIE is a significant factor on the web.” How long will that be? Probably for another year at least. The follow-up post notes that “When Microsoft drops Windows XP support in April 2014, however, it will put a hurt on the oldIE installed base.”
The jQuery core development team acknowledges that continuing to support and fix bugs in jQuery 1.9 while jQuery 2.0 is out is “a departure from the past,” but given the current situation, it makes sense. They emphasized that they won't be leaving any jQuery 1.9 users behind after they release jQuery 2.0, because they “prefer to add new functionality through plugins compatible with both versions where it makes sense.” So programmers should feel free to use whichever version of jQuery makes the most sense based on the browsers their websites must support. Choose your jQuery version based on your visitors' needs.
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