Vulkan on macOS and iOS
Dota 2. © Valve.
Vulkan is the open graphics API that replaced OpenGL and is supported by all platforms, except iOS and macOS, as Apple uses its own Metal API. Game developers who want to create iOS or macOS versions have to use either Metal, which requires a lot of porting work, or OpenGL. Unfortunately, the version of OpenGL which is supported by Apple is becoming more and more obsolete, and has always been clunky. Without any help from Apple, Khronos, Valve, LunarG and Brenwill Workshop decided to step up to the plate and developed a toolbox that allows for on-the-fly conversions of Vulcan to Metal. This will definitely make the portage of many games into iOS or macOS much easier. Valve has already created a macOS/Vulkan version of its title Dota 2, and it's twice as fast as the original Mac version. Under Apache 2 license, use of the tool, named Molten VK, is free.
⇨ Ars Technica, “Vulkan is coming to macOS and iOS, but no thanks to Apple.”