It was originally developed as a multi-user time-sharing system. Multiple users would access the system simultaneously via the attached teletype terminals. The

It was originally developed as a multi-user time-sharing system. Multiple users would access the system simultaneously via the attached teletype terminals. The "shell" program handled such an interactive user session. All IO was blocking, and programs were written in a sequential manner. Piping enabled them to feed the standard output of one process to the standard input of another. It's a good framework for text-based computing, but nowadays we have so much more problems to cope with. This original idea never addressed networking, binary versioning and control, configuration management, async IO, multithreading, GUI, etc.