My first encounter with Forth was through the TinyMUCK codebase, the language was called MUF, and it blew my mind at the time that it was possible to code within the MUD game itself and use it right away.
Wow, memories! MUF taught me stack architecture. I remember printing out reams of its documentation (diagrams in ASCII art, IIRC) on paper and reading through it for fun, just trying to wrap my head around how this crazy thing was supposed to work.
