https://www.developer-tech.com/news/2018/jun/07/game-developers-apple-opengl/

A notice of OpenGL’s deprecation in Apple’s documentation has game developers threatening to abandon the company’s platforms.

OpenGL has been a tried-and-trusted library for cross-platform game developers for decades. Up-and-coming APIs like Vulkan and Apple’s own Metal offer promising alternatives, but many projects still use OpenGL.