While most operating systems are written in C and C++, KolibriOS is written in pure x86 assembly and as a result small and lightweight enough to run off a standard 1.44 MB floppy disk, as demonstrated ...
KolibriOS fits on a single floppy disk, updated as recently as a few months ago. Despite its old-school appearance, it features a full GUI and internet connectivity. If interested, download the image ...
Even in 2025 there are still many applications for a simple Disk Operating System (DOS), whether this includes running legacy software (including MS-DOS games & Windows 3.x), or (embedded) systems ...