[phorese]

Good question :)

I needed a quick way to hack the output of 2D float data (pixel annotations to complement some image) into some legacy C without adding dependencies.

Thanks to CImg, I can read and display the PFM files in 10 lines of my own C++. I thought about just writing a width/height-annotated binary blob instead, but then realized that's really what PFM already is.

I have no idea if anything is really using PFM. I certainly have not found any "big" compatible programs.