OpenEmu is an open-source multi-system game emulator designed for macOS. It provides a plugin interface to emulate numerous consoles' hardware, such as the Nintendo Entertainment System, Genesis, Game Boy, and many more. The architecture allows for other developers to add new cores to the base system without the need to account for specific macOS APIs. Version 1.0 was released on December 23, 2013, after a lengthy beta testing period. Numerous incremental updates have been released since then, with plans to incorporate support for more consoles in future releases. Some of these in-development cores are available to download in an optional "experimental" cores build, containing support for arcade systems using MAME.
History
Beginnings
openwas first released on as OpenNestopia, a Cocoa-port written by Josh Weinberg for then Mac OS X 10.4 Tiger of the NES/Famicom emulator Nestopia. Weinberg and his friend, Ben Devacel, began searching for more developers to port other emulators to macOS, which led to the name change to OpenEmu in 2009, to better describe the multi-system emulator.
Introduced on, OpenEmu 2.0 was released. OpenEmu 2.0 began requiring a minimum of OS X El Capitan 10.11, dropping support for Mac OS X Lion through OS X Yosemite. OpenEmu 2.0 introduced 16 new cores along with hundreds of bug fixes and lesser features. The new cores added several 2nd generation cores, support for optical media-based-image games, additionally emulating systems from Sony, Mattel, Bandai, Magnavox, Milton-Bradley, and Coleco. Another midsteam update, 2.0.6.1, released added support for Mednafen's Sega Saturnbranch, with a suggested quad-core i7 CPU to emulate.
2.1 and 2.2
OpenEmu 2.1 was significant, not for any new cores, but for supporting Metal, Apple's visual API successor to OpenGL and OpenCl, giving OpenEmu significant gains in both performance and battery life. OpenEmu 2.2 added support for a downstream, Metal-forked version of Dolphin's GameCube branch, building on 2.1's foundation. This brings OpenEmu's number of supported cores to 31.
Limitations
32X Hybrid Games
As confirmed by the OpenEmu developers on their official subreddit, Sega 32X-CD hybrid games are not supported. Users are prompted with a "This game requires the Sega 32X attachment" error if attempted.
GameCube Limitations
At present, GameCube emulation doesn't support Save States ; users are encouraged to use in-game saves. OpenEmu GameCube emulation also does not support the at present.
Features
OpenEmu features a backend that uses multiple game engines while maintaining the familiar, native macOS frontend UI. It also uses modern macOS technologies such as Cocoa and Quartz. A unique feature of OpenEmu is its ROM library, which allows one to import ROM files and view them in a gallery type setting, similar to iTunes. Game info and cover art can be automatically added from OpenEmu's databases. OpenEmu includes the following features:
High-quality Metal scaling, multithreaded playback, and other optimizations
* Default core plugin. ** Version 2.1 and lower must have custom system core.
Reception
Upon its 1.0 release, OpenEmu was positively received, and subject to much online press coverage, praising the software's UI, features, and ease of use. In particular, it was praised by the gaming community for " the idea of an emulator for a mainstream, general audience to reality". As of August 16, 2018, OpenEmu has been downloaded over 10,000,000 times since its version 1.0 release, making it one of the most popular multi-system emulators on macOS.
