Jasper by Adam Davidson & Andrew Pollard
Freescape® was the original generic, scriptable cross-platform 3d engine. Designed by Incentive Software, it was first deployed in 1987's Driller and subsequently powered Dark Side, Total Eclipse, Castle Master, Castle Master II: The Crypt and Total Eclipse II: The Sphinx Jinx.
A derivative of the engine was used in 1991 to create the 3d Construction Kit (released in some territories as the Virtual Reality Studio), which allowed home users to design their own scenes and write small programs so as to create entirely new games, which could then be saved in a standalone format and distributed freely irrespective of whether the recipients owned a copy of the kit. This effectively makes Freescape the first licensed 3d engine for games.
The 3d Construction Kit was followed in 1992 with a 16-bit exclusive sequel that added some new primitives and expanded the scripting language. Incentive subsequently left the games market to focus on high-end virtual reality tools.