jQuery 1.11 和 2.1 Beta1 发布了，获取地址：
http://code.jquery.com/jquery-1.11.0-beta1.js
http://code.jquery.com/jquery-2.1.0-beta1.js
别忘了 jQuery 1.x 支持 IE 6/7/8 ，而 jQuery 2.x 不支持，值得关注的改进有：
1. 异步模块定义 AMD
2. 性能提升，降低启动时间
3. Bower support: We’re now using Bower for a lot of our internal dependency management, and plan to publish production versions of jQuery to Bower in the future.
4. Bug 修复
5. API 改动
两个版本都包含如下的改进记录：
Ajax
#14356: Remove string indexing used in AJAX
Attributes
#14250: addClass and removeClass needlessly assign to className.
Build
#13983: Switch to //# for sourcemap directives
#14113: AMD-ify jQuery source
#14118: Use bower to include Sizzle and QUnit (remove submodules)
#14163: Make Deferreds/Callbacks/.ready() optional modules
Core
#14164: Reduce forced layout reflows in init or methods
Css
#14150: IE9-10 curCSS => “Interface not supported” in for popups (and probably frames)
Event
#14282: Don’t call getPreventDefault() if there is a defaultPrevented property
Support
#14084: elem.css(‘width’) provides incorrect output with `box-sizing: border-box` if run before document ready
来自:开源中国社区
