GPGPU before CUDA and OpenCL

Question

I've been reading about CUDA and OpenCL and have learned that before these frameworks developers could only use low level APIs like OPENGL and D3D. Unfortunately I haven't been able to find much information about it.

Was it a widespread or commercial practice or was it just something they used in research and military labs? I'm sure somebody here will have experience with earlier GPGPU programming.

Answer 1

There were a number of approaches to GPGPU before CUDA and OpenCL came along, e.g. the Brook and Cg programming languages.

Answer 2

It was mostly used in research. Of course, some GPGPU techniques was applied for software which needed to put pixels on the screen and for games, but mostly it was a research thingy.