I have done something similar for Linux under 2 KiB in assembly some time ago: https://gaultier.github.io/blog/x11_x64.html https://gaultier.github.io/blog/x11_

I have done something similar for Linux under 2 KiB in assembly some time ago: https://gaultier.github.io/blog/x11_x64.html https://gaultier.github.io/blog/x11_x64.html As others have said, doing so in pure C and linking dynamically, you can easily remain under 20 KiB, at least on Linux, but Windows should be even simpler since it ships with much more out of the box as part of the OS. In any event, I salute the effort! You can try the linking options I mentioned at the end of my article, it should help getting the size down.