Granny 3D
RAD Game Tools' middleware for exporting, storing and playing back animated 3D models — its .gr2 format turns up in more games than most people realise.
Granny takes models and skeletal animation out of 3ds Max or Maya, packs them into its own format, and provides a runtime for compressing, blending and playing animations. Casey Muratori was among its developers. The pitch was the same as for RAD's Bink Video: a dull but hard problem that every studio would otherwise solve on its own, worse.
It has shipped in thousands of titles since the late 1990s, and modders recognise .gr2 files from games that otherwise have nothing in common. Epic Games bought RAD in 2021.