Mike Ormond from Microsoft discusses using jQuery with ASP.NET. jQuery is a popular JavaScript library that simplifies HTML document traversal, event handling, animation, and AJAX interactions. It was created by John Resig and is now the most widely used JavaScript library. Microsoft has invested in jQuery by including it in Visual Studio and providing IntelliSense support. jQuery complements ASP.NET nicely by focusing on client-side AJAX, while tools like the ASP.NET AJAX Control Toolkit focus more on server-side AJAX functionality. Resources for learning more about jQuery and ASP.NET AJAX are provided.