The Wander system was originally written in HP BASIC (for a HP2000 minicomputer) in 1973 or 1974 and later rewritten in C. This game was included in the Peter Langston game collection issued by USENIX for UNIX mainframes.
The source code was recovered in 2015 and has been recompiled for Linux and Windows. There is also a rudimentary DOS port.
For more details see Anthony's Hope blog post about the game.
[+] Users who have solved this game
[+] Users currently playing this game
Very impressive early effort!