I've got an ASP.NET web application, and I'm attempting to reduce HTTP calls to the server, so I'd like to not load things like MicrosoftAjaxWebForms.debug.js and MicrosoftAjax.debug.js.
Script manager is used to form all of my external javascript files into one, and I'm concerned that this is causing other non-related libraries to be loaded.
It is indeed the ScriptManager that is pulling these in. You might be able to reduce the number of scripts it adds by turning off the different features on it, eg. PageMethods.
Look for the properties that starts with Enable...
Of course, it will probably be easier to just create a small method that does the same as the ScriptManager, all it does is add some <script> tags to the document..