This is a basic ASP.NET rule that's easy to forget, but if using the ASP.NET Ajax Control Toolkit with another application like Community Server, we score big if we remember to trim the toolkit of the code we don't need.
The full Ajax Control Toolkit project DLL like the above weighs in at 1332KB when compiled in Debug mode and 764KB in Release mode. We've customized the Toolkit's SlideShow control for Community Server and added a Web Service in the Toolkit project in a /Services folder. So we can exclude (not remove so we can quickly include them later) all of the controls we're not using. The resulting Ajax Toolkit DLL in our Community Server /bin directory is only 220KB.
