[Our XML serialization infrastructure can] (...) translate any given class into XML. It'll actually take the schema for the class, the XSD schema, and will build a specialized parser that derives from our generic XML parser (which is part of the .NET base classes), and then override methods and add logic into the parser so that it is specialized for that schema. So we've instantiated a parser that at native code speed can rip through XML. If it's not correct, we'll give you a nice error message, which tells you precisely what went wrong. Then we cache it in our code-caching infrastructure, and it sits around until the next time a class with an identical schema comes by and it just goes, "Bam!" I mean, incredible, incredible throughput.

In terms of the entire Visual Studio and .NET platform group, we are about a thousand-person division. - Tony Goodhew (C# prodcut manager) in the same interview