I’d like to write a program that uses shaders (mostly for full screen effects like desaturation, cctv simulation, etc). I have quite a wide range of platforms I’d like to support. I’d obviously like to use GLSL but some of the platforms don’t support it (Linux with slightly older Intel GMA hardware, FreeBSD with open Radeon drivers, amongst others). I could use nvidia’s Cg toolkit but frankly the license looks terrifying and it doesn’t support all of the platforms I’m targeting anyway.
What are my options here? Do I really have to forget high level and use GL_ARB_fragment_program?