GX

GX is the API used for interacting with the GP GPU on the GameCube and Wii (and the Wii U in backwards compatibility mode). It is a highly configurable fixed-function API leveraging the TEV units on the GP to allow for a wide variety of texture blending configurations. It is overall similar to OpenGL 1.x, and has some lineage with it due to it being designed by former SGI engineers.

GX is implemented in the official Dolphin and Revolution SDKs, as well as an open reverse-engineered version in libogc.

GX was succeeded on the Wii U by the (largely unrelated?) GX2 API, which is used for programming the GPU7.