A lot has been written about how to get ASP.NET MVC running on IIS 6 with extensionless URLs. Up until now, the story hasn’t been very pretty. When running ASP.NET MVC on ASP.NET 4, it gets a lot easier. To be fair, the part that makes it easier has nothing to do with ASP.NET MVC 3 and everything to do with a little known new feature of ASP.NET 4 creatively called the ASP.NET 4 Extensionless URL feature. ASP.NET MVC 3 requires ASP.NET 4 so it naturally benefits from this new feature. If you have a server running IIS...