Yesterday at WWDC 2018, Apple revealed macOS Mojave, which is set to bring users a Dark Mode, redesigned Mac App Store, organizable Stacks, streamlined screenshots, and more when it launches wide in the fall. Alongside the new features, Apple has confirmed that it is deprecating OpenGL (Open Graphics Library) and OpenCL (Open Computing Language) in favor of Metal.
This means that apps built using OpenGL and OpenCL will still run in Mojave, but they will no longer be updated after macOS 10.14 launches. Apple encourages games and “graphics-intensive apps” built with OpenGL to adopt Metal ahead of Mojave’s launch, and apps that use OpenCL for computational tasks “should now adopt Metal and Metal Performance Shaders.”
This is going to be a major burden for small game developers.