This is not a compiler. It is doing no program translation. No register allocation. No parsing. No linking. It in no way resembles a compiler. Not every program that produces an executable file is a compiler just because some programs you may have heard of, like gcc, are in fact compilers.

I wish the JS universe would stop inventing new and wrong names for things.

(That said, this thing is at least using postject for actual insertion of the payload blob into the target executable, and based on its README, postjecth as the good taste to embed data as PE/ELF/Mach-O sections instead (as Bun does) of just YOLOing the attachment with cat.)