tri-man/ATF
Authoring Tools Framework (ATF) is a set of C#/.NET components for making tools on Windows. ATF has been in continuous development in Sony's Worldwide Studios central tools group since early 2006. ATF has been used by most Sony first party game studios to make many custom tools such as Naughty Dog’s level editor and shader editor for The Last of Us, Guerrilla Games’ sequence editor for Killzone games (including the Killzone: Shadow Fall PS4 launch title), an animation blending tool at Santa Monica Studios, a level editor at Bend Studio, a visual state machine editor for Quantic Dream, sound editing tools, and many others.