I may be mistaken but Wasn't the first release of .NET in Visual Studio .NET 2002? Which makes it only 3-4 Years old (depends how you want to count )
ASP.NET was available to "work with" around 2001, it wasn't until 2002 that developers got an IDE for it. Thus making ASP.NET 5 years old.
Java is much older, but a better comparison would be J2EE Vs. .NET.
I don't think you can compare RoR with ASP.NET given that the whole .NET framework (and almost every Managed API) is available to you. To my knowledge, RoR doesn't have anything like CreateObject/GetObject.