Could anyone please explain why I'm being downvoted? A compiler/interpreter which can compile/interpret two versions of a language is out of this world? I thi

Could anyone please explain why I'm being downvoted? A compiler/interpreter which can compile/interpret two versions of a language is out of this world? I think it's the most pragmatic approach: let people use old libraries while allowing them to develop with the improved language. If I'm not mistaken, ISE Eiffel (now EiffelStudio) can compile both C/C++ and Eiffel sources to make a single executable. ISE Eiffel however is an industrial-strength compiler backed by a great software engineer. Current Common Lisp compilers can compile source code as old as fifty years ago with little or no modifications. Now, that's backward compatibility.