Are you using the Microsoft AJAX framework with your ASP.NET application and are worried about the cost to maintain and serve up the javascript library components along side your application code? Well Microsoft just introduced the Microsoft AJAX Content Delivery Network. They host, mantain and serve the AJAX javascript library on their servers and you can point to their library files at ajax.microsoft.com from within your application <script> tags. Right now it appears to be limited to AJAX Beta 09/2009 related library files, but this is good news for limiting your server bandwidth and improving overall security.