PyInstaller supports making executables for Windows, Linux, and macOS, but it cannot cross compile.

Is there an alternative to PyInstaller?

There are five alternatives to PyInstaller for Windows, Linux and Mac. The best alternative is py2exe, which is both free and Open Source. Other great apps like PyInstaller are cx_Freeze (Free, Open Source), nuitka (Free, Open Source), Shed Skin (Free, Open Source) and bbfreeze (Free, Open Source).

Is Python a cross-platform?

Python is a cross-platform language: a Python program written on a Macintosh computer will run on a Linux system and vice versa. Python programs can run on a Windows computer, as long as the Windows machine has the Python interpreter installed (most other operating systems come with Python pre-installed).