# Comparison with similar systems

To begin with, retrowin32 is relatively immature and cannot execute most
programs.

If you are just looking to run Windows software, I recommend instead using:

- on x86 hardware: [Wine](https://www.winehq.org/)
- on non-x86 hardware: [qemu](https://www.qemu.org/)
- in a browser: [v86](https://copy.sh/v86/) or
  [Boxedwine](https://www.boxedwine.org/)

## Architectural differences

Executing a Windows .exe broadly
[requires two components](https://neugierig.org/software/blog/2023/01/emulating-win32.html):
executing x86 instructions and interpreting the Windows calls.

To run an exe natively requires both an x86 processor and the Windows OS:

<img src='native.png' width='230' alt='Windows component stack'>

[Wine](https://www.winehq.org/) translates Windows calls onto a different OS,
but still requires an x86 processor for the x86 instructions:

<img src='wine.png' width='230' alt='wine component stack'>

On non-x86 platforms (including browsers),
[Boxedwine](https://www.boxedwine.org/) combines Wine with a CPU emulator and
implementation of the bits of Linux that Wine expects:

<img src='boxedwine.png' width='230' alt='boxedwine component'>

x86 emulators like [qemu](https://www.qemu.org/) and [v86](https://copy.sh/v86/)
emulate an x86 processor, but at a level where it still requires you to run the
whole Windows OS within the emulator:

<img src='qemu.png' width='230' alt='qemu component stack'>

Finally, retrowin32 aims to run a win32 executable directly, in a manner similar
to how video game emulators work: by both emulating the executable and mapping
its calls directly into local OS calls.

<img src='retrowin32.png' width='230' alt='retrowin32 component stack'>

Among the alternatives, retrowin32 is most similar to boxedwine. Note that while
this drawing is visually shorter, it still encompasses most of the same
complexity. The primary differences are:

- the bulk of retrowin32's win32 implementation happens outside of the x86
  emulator;
- retrowin32's win32 implementation doesn't depend on any Linux emulation, and
  can target the browser directly instead of SDL.