Aside from a few utilities, relatively little of OS/400 was written in RPG. Originally, most of it was written in two different dialects of PL/I. Some Modula-2 was added into the mix, and most of the lower levels were rewritten in C++ when they switched to PPC processors.
Aside from a few utilities, relatively little of OS/400 was written in RPG. Originally, most of it was written in two different dialects of PL/I. Some Modula-2 was added into the mix, and most of the lower levels were rewritten in C++ when they switched to PPC processors.