[Laforet]

No, but OSX certainly is. I doubt it's viable to write games without using any of the proprietary APIs.

[roblabla]

You can write games just fine using OpenGL (and SDL for windowing/inputs/audio/etc).

[yoz-y]

For now, but in the next version there will probably be no OpenGL support.

[saagarjha]

Doubt it. There are still dozens of frameworks that still link to OpenGL, and Apple’d need to drop or update them all in a year. Most likely it will remain on the system for at least a couple years.

[roblabla]

You'll still be able to use MoltenVK to get Vulkan support, and SDL will still work for windowing and everything else.

[jimmaswell]

I was just referring to the "lesser degree" of being proprietary