Comprehensive (ie. HEAVY!) guide to the way-before it's time BASIC from GFA...
Fun fact, courtesy of WikiPedia:-
Éric Chahi wrote a game editor in GFA basic to create his game Another World, including scene design and game scripting; only the game engine (polygon rendering and music) was done in assembler.
This editor was used to make all ports of the game, including for consoles and the Collector Edition for Windows released in 2006.