Slow? No, it was really fast. And it is in KOS (it's in kos-ports named "libGL").
But although it's fast, it's not without issues. It uses a lot of memory (5M+ baseline) which on a machine with 16M total is pretty limiting. It's also very buggy, it doesn't respect glClientState, has a bunch of issues with strides to glVertexPointer etc, has broken mipmap support etc.
I tried to fix a bunch of these issues but then decided that it would be better to do a complete rewrite so I've started working on that here: https://github.com/Kazade/GLdc
Although mine is currently slow without near-Z clipping. But it is being used for at least 1 game.