jQuery 1.4

jQuery is a free, open source, lightweight cross-browser JavaScript library.  jQuery is the most popular JavaScript library in use today.  (wiki)

In honor of jQuery’s 4th birthday, another major release of the jQuery JavaScript library is now available.  New features and improvements include:

• Performance overhaul of popular methods
• Easy setter functions
• Nested param serialization
• JSON and script types auto-detected by content-type
• Etag support
• Strict JSON parsing, using native JSON.parse
• Serialize HTML5 elements
• Context for Ajax Request
• Quick Element Construction
• .css() method has 2x performance improvement
• Per-property easing
• Event multi-binding
• Better support for applets

Download jQuery 1.4
jQuery 1.4 Overview
jQuery 1.4 Documentation

jQuery Ships with Visual Studio

jQuery is a lightweight open source JavaScript library (only 15kb in size) that has become one of the most popular libraries on the Web.  jQuery enables developers to efficiently find and manipulate HTML elements.  Microsoft will be shipping jQuery with Visual Studio going forward.  Microsoft will distribute the jQuery JavaScript library as-is, and will not be forking or changing the source from the main jQuery branch.  Visual Studio will include jQuery Intellisense and help files.

Read more at Scott Gu’s Blog