Doloto is an AJAX application optimization tool, especially useful for large and complex Web 2.0 applications that contain a lot of code, such as Bing Maps, Hotmail, etc. Doloto analyzes AJAX application workloads and automatically performs code splitting of existing large Web 2.0 applications.
Read more details about this tool in this blog post - http://blogs.msdn.com/somasegar/archive/2009/09/04/doloto-on-devlabs.aspx
Also check other cool projects at MSDN Dev Labs - http://msdn.microsoft.com/en-us/devlabs/dd125421.aspx