No. OpenCL. It something that darktable uses for acceleration, and I had not been able to activate it on Zorin with an AMD card. Ended up swapping out to an Nvidia card, which works fine. I have the AMD card running in Majaro for a couple years, it's an easy one package install from AUR.
Link to the issue here: AMD Radeon OpenCL - #33 by Aravisian