I recently brought Infocom's original UNIX z-machine source code back to life on modern systems. The modified source code, instructions on usage, a build of the z-machine, and examples of embedded game executables are available.
There is also a detailed write-up about the state of the original source code, the porting process, and the invaluable role Justine Tunney's Cosmpolitan project played in bringing the Zork trilogy (and more) to Windows/Mac/Linux/bsd for arm/x86 machines over the course of a lazy Sunday.