Hi there!
We do support pretty much everything ASP.NET, including MVC2/3. We tested 
MVC3/Razor sample and had no problem running it under 
UltiDev Web Server Pro. When registering the application just leave default document field blank and that's all.
If you plan to redistribute your applications with UWS, you will need include MVC3 framework in your installation.
Best regards,
UltiDev Team.
Please donate at 
http://www.ultidev.com/products/Donate.aspx to help us improve our products.