OpenEmu
OpenEmu is an open-source project whose purpose is to bring macOS game emulation into the realm of first-class citizenship. The project leverages modern macOS technologies, such as Cocoa, Metal, Core Animation, and other third-party libraries. One third-party library example is Sparkle, which is used for auto-updating. OpenEmu uses a modular architecture, allowing for game-engine plugins, allowing OpenEmu to support a host of different emulation engines and back ends while retaining the familiar macOS native front end.