jQuery is a lightweight open source JavaScript library (only 15kb in size) that in a relatively short span of time has become one of the most popular libraries on the web.
Scott Hanselman is also about to post a nice tutorial that shows off integrating jQuery with ASP.NET AJAX (including the new client templating engine) as well as ADO.NET Data Services (which shipped in .NET 3.5 SP1 and was previously code-named “Astoria”).
