BareMetal

Programs that compile to run directly on the computer hardware without an explicit OperatingSystem (though I guess they have a kind of LibraryOS compiled in with them)

See :

• BareMetalRaspi for things that compile to bare metal on the RaspberryPi
• BareMetalSmalltalk for SmallTalks built on bare metal
• LispMachines for equivalent for LispLanguage
• Arduino and similar SingleBoardComputers are often without OS.