Yes, Mantle is older. But after Mantle came out, my impression is that the OpenGL committee intended to deliver a new version of OpenGL, rather than rewrite it.

Yes, Mantle is older. But after Mantle came out, my impression is that the OpenGL committee intended to deliver a new version of OpenGL, rather than rewrite it. I think of the timeline like this: Mantle comes out and it shows that you can deliver performance improvements with a new API that more closely reflects the hardware. Microsoft goes off and starts working on DirectX 12, to bring those benefits to DirectX. OpenGL starts working on a new version of OpenGL, to bring those benefits to OpenGL, but the progress is somewhat slower. Apple works on Metal internally, so it doesn’t have to wait for a new OpenGL and doesn’t have to deal with committees. Khronos sees that they’re being left behind, and kicks off OpenGL Next. Rough timeline: 2013: AMD makes Mantle (no GA). 2014: OpenGL AZDO talks. Apple delivers Metal 1.0. Khronos kicks off the Vulkan project, then named OpenGL Next. 2015: OpenGL Next renamed as Vulkan. Microsoft delivers DirectX 12. 2016: Vulkan 1.0.