OpenGL vs Metal: what is the difference for cross-platform game development?

OpenGL uses GLSL, a C-based shading language, while Metal uses the Metal Shading Language, a derivative of C++14 that lets developers write shaders with classes and templates. That difference in tooling reflects a bigger split: OpenGL renders on nearly any platform a game ships to, and Metal renders only on Apple hardware.

How do the shader languages differ for a game team?

GLSL is close enough to C that most graphics programmers pick it up quickly, but it stays a small, purpose-built language with no object-oriented features. Metal Shading Language builds on C++14, so it supports classes, templates, and namespaces, though Apple strips out features like virtual functions and exception handling to keep it fast on the GPU. A studio that already writes gameplay code in C++ finds MSL syntax familiar, while a studio maintaining shaders across several APIs usually keeps GLSL as the common denominator and converts it for Apple builds.

What does OpenGL give a team shipping to several platforms?

A single OpenGL, or OpenGL ES, renderer still covers Windows, Linux, Android, and legacy iOS and macOS builds without a second graphics backend. That coverage is shrinking: Unreal Engine removed its OpenGL ES2 mobile renderer in version 4.25 and now defaults new mobile projects to Vulkan on Android and Metal on iOS. Studios that kept OpenGL running did so mainly to support older devices or engines that never migrated, not because it still leads on performance.

Where does Metal help a game built for Apple hardware?

Metal gives direct control over the GPU command queue and memory, which lowers CPU overhead for demanding titles on iPhone, iPad, and Mac. Xcode's Metal debugger and GPU frame capture tools show exactly where a frame spends its time, a level of built-in profiling OpenGL never had on Apple devices. The tradeoff is scope: none of that tooling or performance work carries over to a Windows or Android build, so a Metal-only renderer means maintaining a separate rendering path for every other platform.

A cross-platform game that must ship the same build to Windows, Android, and older Apple devices still leans on OpenGL or a broader API layer, while a game built specifically for current Apple hardware gains more from Metal's lower overhead than it loses by dropping other platforms.