Standalone program
A stand-alone program is a computer program that does not load any external module, library function or program and that is designed to boot with the bootstrap procedure of the target processor – it runs on bare metal. In early computers like the ENIAC without the concept of an operating system, standalone programs were the only way to run a computer. Standalone programs are usually written in or complied to the assembly language for the specific hardware.
Later standalone programs typically were provided for utility functions such as disk formatting. Also, computers with very limited storage used standalone programs, i.e. most computers until the mid-1950s, and later still embedded processors.
Nowadays, standalone programs are a nearly extinct species of programs. Even the most basic processors these days have sufficient storage to allow the operating system overhead, and if this is still a problem, basic general purpose operating systems are available for that purpose. E.g. in the diskette era, apparently standalone utility programs were delivered with a basic version of DOS fitting onto the same diskette.