From Gamehiker Wiki
|Developer||Nintendo, Hudson, Sharp|
|System||Nintendo Entertainment System|
|Release Date|| Nintendo Entertainment System|
JP June 21, 1984
Family BASIC is a program jointly developed between Nintendo, Hudson, and Sharp for the NES. It came with an instruction booklet as well as a Family BASIC Keyboard.
There were plans to release Family BASIC outside of Japan, but they were ultimately abandoned. Nintendo didn't want the NES to be viewed as a computer system.
Family BASIC wasn't actually a game; it was a programming language so people could make their own games. Games could be saved using the Famicom Data Recorder. Interestingly, the game included background elements from Donkey Kong, Donkey Kong Jr., and Mario Bros..
There were actually three versions of Family BASIC. The first one was never released to the public. The third one had some changes including a simplified interface and premade games.
Also, several popular games, including Excitebike and Lode Runner, were programmed using Family BASIC.