"I have no idea what Apple or Google are doing software wise, if they have the equivalent of C# and .NET."

Apple has objective C which you use with XCode, and Google uses the original .NET. It's called Java. It was created far before Anders Hejlsberg, the MSJVM WFC lead(remember J++), decided to "borrow" it when Sun told him he couldn't create non JNI Win32 extensions.