Cross-Compiling Common Lisp for Windows

Lucid Common Lisp used to have cross-compilation features built-in: https://www.dreamsongs.com/Files/cp.pdf

The approach is somewhat interesting: They model the different platforms the code will run on as classes and set them up to inherit from one another, which drives the optimization possibilities, register allocations and the code generation. Because of the inheritance, they claim that porting to neighboring CPU families is easy since they don't have to duplicate the code for the instruction set mappings, etc. and only specialize the certain parts that are different.

Wouldn't Cosomoplitan be the true cross-compiling in this case?

https://github.com/jart/cosmopolitan

I'm going to be that guy and say "this isn't cross-compiling." I was thinking "Why not just use Wine" when I clicked on the link, and that's what they are doing.