A little history: Unix


The Unix system comes from the Multics experience
(multiprogrammed-computer system) and is written
for fun by Bell-Labs people (AT&T),
on an unused computer.

The main features of the system are:

Multiuser capability
Multiprocess capability (as time sharing)
Peripheral access made like file access
Pipes and sockets (new concepts)
The "controlling tty" (new concept)