A few pieces of Delphi compiler history:
Allen Bauer:
Most notably, the Object Pascal/Delphi compiler is written in mostly C with a smattering of C++, the editor kernel (sans display rendering) and debugger engine (process control/symbol table management) were written in C++. All of which I’ve worked on throughout my 24+ years on that team.
The 16bit compiler was written in pure assembler. The current compiler is written in C. It was derived from an Amiga 68000 Turbo Pascal compatible compiler. It’s never been written in Object Pascal.
That being said, there was an effort several years ago to completely rework/re-architect the compiler. That was done in OP. It just barely got to the “hello world” stage before it was set aside.
Source: The Oracle at Delphi: Set in my ways [WayBack]
–jeroen