Okay, `WriteLn('Hello World!');` with modified Free Pascal Compiler (codename #BitJet) now down to 4kB on the #AmstradCPC!

Nice progress, 33k -> 8k -> 4k, with compiler optimizations.

@RetroFunPL even still... ...
@Jayenkai the app code is below 300 bytes, the challenge is to provide the built-in libraries without the things you don't, or can't, use
@Jayenkai it's also the price for including, among others, full heap memory management -- figured that would be useful.