Mesen

What Mesen is

Mesen is a free, open-source emulator for Windows, Linux, and macOS. It supports NES, SNES, Game Boy and Game Boy Color, Game Boy Advance, PC Engine, SMS and Game Gear, and WonderSwan and WonderSwan Color. The official site lists version 2.2.1, released June 5, 2026. Its release notes report accuracy improvements for NES CPU, APU, and PPU emulation, as well as PAL and Famicom Disk System accuracy; they also list link cable support between two Game Boy or Game Boy Color consoles. The older Mesen page describes debugging tools for homebrew development and ROM hacking. The project is becoming MesenCE, maintained by Sour and community members. Mesen is licensed under the GNU General Public License version 3 or later. Windows requires version 10 or later. Linux and macOS builds require SDL2, and macOS builds are self-signed and need Gatekeeper approval before running. Development builds cover Windows, Linux x64 and ARM64, and macOS Intel and Apple Silicon.

Who it suits

Mesen suits people who want a free desktop emulator for its supported systems. Its described debugging tools may also suit homebrew developers and ROM hackers.

Getting started

1. Visit https://www.mesen.ca/.
2. Choose a build for Windows, Linux, or macOS.
3. Use Windows 10 or later for the Windows build.
4. Install SDL2 before using the Linux or macOS build.
5. Approve the self-signed macOS build through Gatekeeper before running it.
6. For SteamOS, follow the separate instructions linked from the repository README.

Verdict

Mesen covers a broad list of systems across three desktop operating systems at no cost. Check the SDL2 and Gatekeeper requirements for your setup before installing.