Desktop

Three host ports share the language and skip the SoC: unix, windows and webassembly. Use them to test scripts, embed the VM, or run Python in a page.

unix / Windows

Build from source (make -C ports/unix). You get a micropython binary, the stdlib subset, sockets on the host OS, and no machine.Pin. This is the fastest way to run the test suite and mpy-cross.

WebAssembly

Official micropython.mjs + micropython.wasm. PyScript’s <script type="mpy"> uses it. Good for language demos; not a substitute for a Pico emulator if you need pins. See embed and tools / embed.

QEMU

Some MCU ports can be built for QEMU (Cortex-M machine). That is closer to a device than the unix port, and is how parts of the CI run. It is still not a full Pico or ESP32 peripheral model — use emulators for that.