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 packs a full graphical desktop into ≈1.3MB and boots almost instantly. Built in Assembly, it's incredibly small, snappy, and includes many apps and games, even Doom. Internet is limited: ...