Reactive Extensions for .NET (Rx)

Reactive Extensions for Javascript. This port brings the power of Reactive programming to JavaScript. It allows you to use the Rx combinators in JavaScript, and it does this in a download size of less than 7Kb (GZipped). RxJS provides easy-to-use conversions from existing DOM, XmlHttpRequest, and jQuery events to Rx push-collections, allowing users to seamlessly plug Rx into their existing JavaScript-based web sites

http://msdn.microsoft.com/en-us/devlabs/ee794896.aspx