I’m guessing not to be confused with REDEngine, the main driver of Cyberpunk 2077 and the Witcher series of games? REDEngine has its own language is my understanding.

Red the language came along in 2011 - the same year as Witcher II used REDEngine for the first time. So I guess I can see where some confusion can arise.

Red is a general programming language, instead of a game engine's personal DSL.