Arguably the first iteration of that was Sketchpad (1963). You had a template with rules, then you could change parameters (e.g. size) and it'd apply the templa

Arguably the first iteration of that was Sketchpad (1963). You had a template with rules, then you could change parameters (e.g. size) and it'd apply the template rules to the new input. Here's an Alan Kay talking about it in 1987: https://archive.org/details/AlanKeyD1987?start=249.5 https://archive.org/details/AlanKeyD1987?start=249.5