openMSX
openMSX is a free, open-source emulator for the MSX home computer system, designed to emulate it with 100% accuracy.
What openMSX is
openMSX is a free, open-source emulator for the MSX home computer system, designed to emulate it with 100% accuracy. It covers almost all MSX, MSX2, MSX2+, and turboR systems, as well as several other systems on an experimental basis. The project lists more than 230 machine configurations and more than 110 extension hardware configurations. A built-in graphical interface works across supported operating systems. Users can control the emulator with Tcl scripts or a command interface over pipes or a UNIX domain socket; external applications can connect through that interface, and MIDI connectivity is available through host frameworks on Windows, Mac, and Linux. The built-in debugger includes watchpoints, breakpoints, viewers, and real-time data display. Save states and a reverse feature let users replay actions or step back in time. Downloads include Windows, macOS, Linux, and Android builds, though listed release versions vary by platform. openMSX 20.0 and later requires OpenGL 2 support. Android support is listed only through version 0.15.0, and the default C-BIOS machine does not provide all functionality for a complete MSX machine. Catapult is deprecated; the project recommends its built-in GUI for version 20.0 and later.
Good
- Emulates MSX, MSX2, MSX2+, and turboR systems.
- Includes over 230 machine configurations.
- Provides save states and a reverse feature.
- Built-in GUI works across supported operating systems.
- Debugger includes watchpoints and breakpoints.
Watch out
- Version 20.0 and later requires OpenGL 2 support.
- Android support is listed only through version 0.15.0.
- Default C-BIOS lacks some complete-machine functionality.
- Catapult is deprecated and no longer maintained.
Who it suits
It suits people who want to emulate MSX systems and use features such as save states, reverse playback, or debugging. Users setting up a complete MSX machine should account for the C-BIOS limitation and consult the setup guide.
Verdict
openMSX offers broad MSX emulation alongside scripting, debugging, save states, and reverse playback. Check the platform-specific version limits and setup requirements before choosing it.
Plans and prices
From openMSX's own pricing page, checked 9 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| openMSX | Free | MSX emulator; downloads and source code available |
The facts
Each one read from openMSX's own pages, with the date it was checked.
Where it runs
- Android limit
- The features page lists Android 4.1+ support only up to openMSX 0.15.0.checked 9 Oct 2026
- Machine configurations
- The project says it includes over 230 MSX and similar machine configurations and over 110 extension hardware configurations.checked 9 Oct 2026
- Platforms
- The feature page lists Linux, Windows 7 or later, macOS, and Android 4.1 or later through openMSX 0.15.0; current downloads include Windows, macOS, Linux, and an older Android APK.checked 9 Oct 2026
What it does
- Built-in GUI
- It includes a graphical user interface that works the same across supported operating systems.checked 9 Oct 2026
- Debugger
- The built-in debugger includes watchpoints, breakpoints, viewers and real-time data display.checked 9 Oct 2026
- Downloads
- The download list includes Windows, macOS, Linux x86 64-bit, Android ARM and source code builds; listed release versions differ by platform.checked 9 Oct 2026
- Emulated systems
- It emulates almost all MSX systems, including MSX, MSX2, MSX2+, and turboR generations.checked 9 Oct 2026
- External integrations
- The command interface can connect openMSX to external applications, and MIDI connectivity is available through host frameworks on Windows, Mac, and Linux.checked 9 Oct 2026
- Graphical interface
- It includes a built-in graphical user interface that works the same across supported operating systems.checked 9 Oct 2026
- Graphics requirement
- The project says openMSX 20.0 and later requires a system with OpenGL 2 support.checked 9 Oct 2026
- GUI status
- Catapult is deprecated and no longer maintained; the documentation recommends the built-in GUI in openMSX 20.0 and later.checked 9 Oct 2026
- Hardware emulation
- It emulates almost all MSX, MSX2, MSX2+ and turboR systems, plus several other systems on an experimental basis.checked 9 Oct 2026
- Hardware library
- The feature page lists over 230 machine configurations and over 110 extension hardware configurations.checked 9 Oct 2026
- Host connectivity
- MIDI connectivity lets applications on Windows, Mac and Linux connect to MIDI devices in the emulated MSX.checked 9 Oct 2026
- Legacy GUI
- Catapult is no longer maintained; the project encourages using the built-in GUI in openMSX 20.0 and later.checked 9 Oct 2026
- Purpose
- openMSX is an emulator for the MSX home computer system that aims to emulate it with 100% accuracy.checked 9 Oct 2026
- Reverse and save states
- It supports save states and a reverse feature for replaying actions or stepping back in time, with optional event-history recording.checked 9 Oct 2026
- Save and rewind
- It supports cross-platform save states and a reverse feature for replaying actions or stepping back through time.checked 9 Oct 2026
- Scripting and control
- Tcl scripts and a command interface over pipes or a UNIX domain socket let users and external applications control openMSX.checked 9 Oct 2026
- Security and compliance
- The official site does not provide security or compliance claims on the pages reviewed.checked 9 Oct 2026
- Setup limitation
- The documentation says the default C-BIOS machine does not provide all functionality for a complete MSX machine and points users to a setup guide for configuring actual MSX machines.checked 9 Oct 2026
- Support
- Users can ask questions in the Discord channel or IRC, use the openMSX forum, or file bugs and feature requests in GitHub’s issue tracker.checked 9 Oct 2026
- Support and documentation
- The project provides online manuals and documentation, and links to an MSX forum and its contact page.checked 9 Oct 2026
- Technical requirement
- The site says openMSX 20.0 and later requires a system with OpenGL 2 support.checked 9 Oct 2026
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