Unix, Object-Orientation, and the OOP Wave

Unix was created at Bell Labs beginning in 1969 by Ken Thompson and Dennis Ritchie, initially written in assembly language for a PDP-7 minicomputer. In 1973, the operating system was substantially rewritten in C, making it one of the first major operating systems built largely in a high-level language rather than assembly. This decision made Unix remarkably portable across different hardware, since only a small kernel core needed rewriting for each new machine, and it cemented an enduring, mutually reinforcing relationship between Unix and C that shaped decades of subsequent operating systems, including Linux, the various BSD variants, and macOS's Darwin core.