Z:gnu-www-ja-gnu-linux-faq--ce81ce-By contrast, an operating syst/en

By contrast, an operating system consists of complex components that can be developed in any order. When you have developed most of the components, most of the work is done. This is much more like the International Space Station than like a house. If most of the Space Station modules were in orbit but awaiting one other essential module, that would be like the GNU system in 1992.