The Fantasy Trip is, presumably, the first point-buy role-playing game system published and the first published by Steve Jackson who later went on to create GURPS.
In 1979, Metagaming published two quick tactical systems for weapons and magic called, respectively The Fantasy Trip: Melee, and The Fantasy Trip: Wizard. These games could be learned in as little as 30-60 minutes and played in 15-30 minutes. In 1980, Metagaming published TFT: In The Labyrinth (which pulled the former together into a full role playing game), along with TFT: Advanced Melee and TFT: Advanced Wizard.
The system was notable for not only being the first point-buy system but the first system that allowed the players to build characters to suit their imaginations without class limitations (although wizards paid twice as much for mundane skills and mundane characters paid twice as much for spells), and without strict leveling (experience went directly to buy stats which allowed new skills and spells). It also included rules to allow players to create their own spells as an in-game player activity.
This game system inspired and set the foundation for The HERO System (beginning with Champions), GURPS, and other point-buy systems emphasizing the uniqueness of each character and the imagination of the player.
Later house rules published in Interplay, the Metagaming house magazine, expanded the skill set into Science Fiction and other genres. Unfortunately, Steve Jackson and Howard Thompson (owner of Metagaming) had a falling out and the company collapsed in the early '80s.
Characters are built by distributing points among attributes (of which there are strength, dexterity, and intelligence) and skills are selected from intelligence-rated groups. The number of skills or spells is limited by the intelligence of the character. Strength limits weapon selection and the strength and duration of spells. The die-system is d6 based with extremely easy checks being 2D6 less-or-equal stat and hard checks at 4D6 <= stat (conceivably harder checks would be possible).