Developer builds a working x86-64 operating system from scratch in four days

LimonOS Custom x86-64 Kernel

LimonOS is a 64-bit monolithic kernel written in C, booting through Limine with its own GDT, IDT, PS/2 drivers, a windowed desktop, and a hand-rolled TLS 1.3 stack. It ships Citrus, a text-only browser that renders DOM and CSS, plus a package manager and an AI terminal. The author, who used an AI assistant but insists he can explain every line, is now slowing down to focus on stability and tests.