Patent issues

[983]

Checking the sign of u^2 - v on the GPU appears to be patented by Adobe in the US.
There also are about 21 patents by Nvidia (click on the "20 More" link) that might or might not apply.

EDIT: This seems to be working around some of the patents:
http://wdobbie.com/post/gpu-text-rendering-with-vector-textures/