I don't understand why people care about this sort of thing. Frameworks are just tools, and sometimes the most expedient tool for some particular job might not be the flagship toolchain for the technology company in question. The handling of promotions on the Apple site might be outsourced to another company which might just happen to use .NET, for example. If some small part of apple.com runs on .NET, that doesn't seem like an earth-shattering revelation to me (apple.com itself is running Apache 1.x + mod_perl on Darwin, it seems).
The odd machine at the microsoft.com domain is probably running Apache on Unix, and similarly for various servers at other technology companies. The web framework/OS is just a tool -- get over it.