OK, What is UNIX?
Possible Operating System Designs:
One User
Many Users
One Task/User
DOS
VM, MVS
(mainframe OS's)
Many Tasks/user
NT, Win2K, OS/2
(Win95/98)
UNIX
UNIX was designed by Bell Labs
in the early 70's, along with the C language.
First practical multi-user, multi-tasking system.
Rapidly adopted by universities, large corporations.
Used to develop (and still runs) the Internet.
Implemented on everything from Cray to Apple.
Several "flavors", slightly different:
System V (Bell Labs)
BSD (Berkeley)
Proprietary - AIX, Solaris, HPIX, etc. (Mostly varieties of BSD)
Linux (closer to System V, some features from BSD)