A still-early Windows emulator for web (and non-Windows native platforms).

Take a win32 .exe file and run it in a web browser or a Mac.

Doesn't really work for much yet, but I'm still tinkering!

• 2023/10: preliminary support for using Unicorn (basically QEMU) for x86 emulation.
• 2023/08: new blog post about new Rosetta-based emulation support. retrowin32 now can run on web, native with CPU emulation, or Rosetta x86-64. (Native x86-64 ought to be relatively easy to add too.)
• 2023/05: new blog post.
• 2023/04: "monolife" demo now can sorta render first scene.
• 2023/02: can now run natively via SDL. See blog post.
• 2022/10: released. Barely runs a few console programs and one DirectDraw program. See blog post.

See some demos.

Software today is written in a world where the platform continually changes -- code you release today may stop working next year as the APIs and deprecations churn. You know what doesn't change? Dead platforms. Old video games written for a NES will work forever because the NES won't ever change again.

win32, the Windows 32-bit API, is such a platform. "win32 is the stable Linux userland ABI" is the observation that it might actually make sense for video game developers aiming for Linux to target the Windows API (which doesn't change) and rely on some translation layer to manage the Linux part (which always changes).

Today there are all these old .exe files lying around that are increasingly hard to run. Even on Windows itself, there's a 32-bit Windows translation layer when running on now standard x86-64 hardware. On non-Windows the best tool is Wine, but it requires x86 hardware. On a recent non-x86 Mac their x86 emulator dropped 32-bit support, so even Wine isn't sufficient there.

So my idea is this: what if you treated a win32 executable in the same way you treat a NES ROM -- as machine code for a CPU you no longer have, expecting hardware and an OS that doesn't exist? retrowin32 is an emulator that interprets the x86 instructions and implements the Windows OS API such that a win32 executable can run directly, without the Windows OS or an x86 beneath it.

See a comparison against other Windows emulator approaches (WINE, qemu, v86) for how this is similar but different.

See HACKING.md to get started on the code.