Interactive Systems Corporation

Interactive Systems Corporation (styled INTERACTIVE Systems Corporation, abbreviated ISC) was a US-based software company and the first vendor of the Unix operating system outside AT&T, operating from Santa Monica, California. It was founded in 1977 by Peter G. Weiner, a RAND Corporation researcher who had previously founded the Yale University computer science department and had been the Ph. D. advisor to Brian Kernighan, one of Unix's developers at AT&T. Weiner was joined by Heinz Lycklama, also a veteran of AT&T and previously the author of a Version 6 Unix port to the LSI-11 computer.

ISC was acquired by the Eastman Kodak Company in 1988, which sold its ISC Unix operating system assets to Sun Microsystems on September 26, 1991. Kodak sold the remaining parts of ISC to SHL Systemhouse Inc in 1993.

Several former ISC staff founded Segue Software which partnered with Lotus Development to develop the Unix version of Lotus 1-2-3 and with Peter Norton Computing to develop the Unix version of the Norton Utilities.

ISC's 1977 offering, IS/1, was a Version 6 Unix variant enhanced for office automation running on the PDP-11. IS/3 and IS/5 were enhanced versions of Unix System III and System V for PDP-11 and VAX. ISC Unix ports to the IBM PC included a variant of System III, developed under contract to IBM, known as PC/IX (Personal Computer Interactive eXecutive, also abbreviated PC-IX), with later versions branded 386/ix and finally Interactive Unix System V/386 (based on System V Release 3.2). ISC was AT&T's "Principal Publisher" for System V.4 on the Intel platform. ISC was also involved in the development of VM/IX (Unix as a guest OS in VM/CMS) and IX/370 (native Unix on the System/370). They also developed the AIX (Advanced Interactive Executive) for the IBM 6150 RT, again under contract to IBM, although IBM awarded the development contract for AIX version 2 for the PS/2 to the competing Locus Computing Corporation.

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