So when a game says 'draw a square on the screen,' the Mac does what it's told. The easiest way to think about it is as a compatibility layer that translates Windows Application Programming Interface (API) calls into something that the Mac can understand. It's been around the Unix world for a very long time, and because OS X is a Unix-based operating system, it works on the Mac too.Īs the name suggests, Wine isn't an emulator. Wine is a recursive acronym that stands for Wine Is Not an Emulator. OS X is POSIX-compliant, too (it's Unix underneath all of Apple's gleam, after all), so Wine will run on the Mac also. It's called The Wine Project, and the effort continues to this day. More than 20 years ago, a project was started to enable Windows software to work on POSIX-compliant operating systems like Linux. The Mac isn't the only computer whose users have wanted to run software designed for Windows.