smolOS
A tiny and simple research operating system
...Its goal is to demonstrate the fundamentals of how an OS boots, handles input, and displays output using only the most essential code. smolOS fits in a single boot sector and runs directly on BIOS-compatible hardware or emulators like QEMU. It’s ideal for those seeking to understand bootloaders, BIOS interrupts, and ultra-low-level system programming through a practical and tiny project.