you consider iOS open, because there is jailbreaking (which I do since 3G in 2008). using the world jail is ironic indeed. in a way you are saying that a jail is inherently open, because you can escape it (it does not matter how easily or hard it is). same as official mac hardware has open options, because you can build hackintosh. or macOS has GPU driver/API options, because you can build hackintosh with NVIDIA GPU and drivers. we really do differ in definitions and world views. 
90% closed source, but that does not make a system inheritinly closed.
0.1% is enough for me to say it is closed as i cannot unlock all doors. and me being able to forcefully break in the doors does not make it open either.
CUDA and OpenCL and will vastly outperform OpenGL
I am not talking about OpenGL as something I’m willing to do GPGPU on. And I find myself into position where game engines can’t help me to achieve custom goals. Yes, I like it for specific reasons. You should really look at what cc is about - s+v+m is a nice overview. these galleries do not get updated, but still oF gallery, Cinder gallery, processing gallery. or vimeo using keywords.
We can leave this conversation at mutual agreement to disagree with each other