Interesting that the language of choice is Delphi. Presumably because it is a teaching language and easy to pickup quickly.
The reason delphi is used is because the majority of this stuff is for Windows. Delphi has a LOT of stuff that makes development way way faster than say c++ when you are dealing with windows -- and the majority of these HAVE to use something lower level because of 'interesting' security implications that you can't utilize in stuff like the CLR (via c#)