> Like every early OS UNIX had very little in the way of userspace services so a pragmatic hack was to use the notion of well known directories to locate things

> Like every early OS UNIX had very little in the way of userspace services so a pragmatic hack was to use the notion of well known directories to locate things like man pages or binaries. > DOS didn't offer any services that required registration so users got used to the idea of organizing programs into directories as they wished, and the background in cheap and heterogenous hardware meant that programs were often in semi-random locations determined by things like how many floppy drives or hard disks the computer owner had purchased. But both systems had PATH from like, almost from the beginning, yet on UNIX, people mostly kept putting stuff into a common (cess)pool of /usr/bin and /usr/lib while on the DOS/Windows side of things each program generally got its own separate directory. You can even see this in the difference of the .so/.dll searching logic: on Windows, you put a .DLL next to the executable to do something similar to the LD_PRELOAD trick.