Most operating systems, or the most popular operating systems? The most important distinction between evolution and design, IMO, is that evolution bars foretho

Most operating systems, or the most popular operating systems? The most important distinction between evolution and design, IMO, is that evolution bars forethought, and any refactoring that trips local optima (which in this case, would be breaking backwards-compatibility). Popular OSes are popular mainly because of their backwards-compatibility and momentum, and are therefore typically unable to be redesigned in any non-evolution fashion.