Among the earliest digital interactive software creations still actively accessed, studied, and played by enthusiasts on vintage hardware, emulators, and historical computer archives are Tennis for Two (1958) and Spacewar! (1962). While Spacewar! was developed on PDP-1मिनicomputers at MIT, text-based simulation games and academic mainframe programs from the early 1960s continue to be maintained by computer history museums, retro-computing preservation societies, and dedicated emulation programmers worldwide.