<operating system> /yoo'niks/ (Or "UNIX", in the authors' words, "A weak pun on Multics") Plural "Unices". An interactive time-sharing operating system invented in 1969 by Ken Thompson after Bell Labs left the Multics project, originally so he could play games on his scavenged PDP-7. Dennis Ritchie, the inventor of C, is considered a co-author of the system. The turning point in Unix's history came when it was reimplemented almost entirely in C during 1972 - 1974, making it the first source-portable OS. Unix subsequently underwent mutations and expansions at the hands of many different people, resulting in a uniquely flexible and developer-friendly environment. By 1991, Unix had become the most widely used multi-user general-purpose operating system in the world. Many people consider this the most important victory yet of hackerdom over industry opposition (but see Unix weenie and {Unix conspiracy} for an opposing point of view). Unix is now offered by many manufacturers and is the subject of an international standardisation effort [called?]. Unix-like operating systems include AIX, A/UX, BSD, Debian, FreeBSD, GNU, HP-UX, Linux, NetBSD, NEXTSTEP, OpenBSD, OPENSTEP, OSF, POSIX, RISCiX, Solaris, SunOS, System V, Ultrix, USG Unix, {Version 7}, Xenix. "Unix" or "UNIX"? Both seem roughly equally popular, perhaps with a historical bias toward the latter. "UNIX" is a registered trademark of The Open Group, however, since it is a name and not an acronym, "Unix" has been adopted in this dictionary except where a larger name includes it in upper case. Since the OS is case-sensitive and exists in many different versions, it is fitting that its name should reflect this. {The UNIX Reference Desk (http://geek-girl.com/unix.html)}. {Spanish fire extinguisher (ftp://linux.mathematik.tu-darmstadt.de/pub/linux/people/okir/unix_flame.gif)}. [Jargon File] (2001-05-14)

The term "Research Unix" refers to early versions of the Unix operating system for DEC PDP-7, PDP-11, VAX and Interdata 7/32 and 8/32 computers, developed in the Bell Labs Computing Sciences Research Center (CSRC).