os8088: A powerful Mac-like OS for the IBM XT, 286, 386
Summary
os8088 is a Mac-like graphical OS for the IBM PC/XT family, implemented in NASM with a 40KB kernel and pre-emptive multitasking. It boots from floppy, runs without DOS, fits in 256K RAM, and demonstrates multitasking, windowing, and loadable applications on early hardware, with browser demos and real hardware tests.