i know it sounds crazy but, i just want to ask if is a compiler support multi programming language? like Delphi could also support C/C++/C# etc? if there is, please let me know. or how?
The GNU Compiler Collection includes front ends for C, C++, Objective-C, Fortran, Java, and Ada
С++ Builder's projects can have both C++ and Pascal (Delphi) code in the same project. Just add existing or create a new .pas-file to C++ project. It will be compiled by C++ Builder (like it was C++ code).
The opposite is not true: Delphi can not compile C++ code.
GCC can be considered as unique compiler even though indeed it's made of several binaries... but you can call it always as gcc and supports C, C++, Objective-C and few more (a lot more indeed, theoretically: one language per available front-end). At the beginning gcc meant GNU C Compiler, but then started to support more languages and the acronym became GNU Compiler Collection.
Borland Rad Studio 2007 does C#, Delphi.NET, C++ (and with that also the C subset) and Delphi.
In later iterations, .NET support was abandoned.
But note that, like afaik GCC, these are in fact separate compiler binaries, with a common frontend that executes them.