Zork is an early example of what these days is called "interactive fiction", but was know as a "text adventure" back in the days when all computing was text-based. Zork accepts simple instructions like "take axe" and "look at box" as input to what is essentially a puzzle-solving exercise. CP/M is an early operating system, originally for microcomputers with floppy drives, but eventually for early hard drives. Almost nobody under the age of 50 remembers using CP/M when it was the latest and greatest, but its legacy lives on in MS-DOS, which it inspired.
CP/M was originally developed for 8080 microprocessors, but was more widely used with the Z80. To run CP/M on Linux, probably the easiest approach is to use a Z80 emulator.
