>"The final Xenix work at Microsoft was an effort with AT&T to integrate Xenix support into the main System V.3 source code, producing what we unimaginatively c

>"The final Xenix work at Microsoft was an effort with AT&T to integrate Xenix support into the main System V.3 source code, producing what we unimaginatively called the “Merged Product” (noted by the official name of “UNIX System V, r3.2” in the timeline above)." https://en.wikipedia.org/wiki/UNIX_System_V https://en.wikipedia.org/wiki/UNIX_System_V >"SVR3 AT&T's UNIX System Development Laboratory (USDL) was succeeded by AT&T Information Systems (ATTIS), which distributed UNIX System V, Release 3, in 1987.[12] SVR3 included STREAMS, Remote File Sharing (RFS), the File System Switch (FSS) virtual file system mechanism, a restricted form of shared libraries, and the Transport Layer Interface (TLI) network API. The final version was Release 3.2 in 1988, which added binary compatibility to Xenix on Intel platforms (see Intel Binary Compatibility Standard). [...] SCO UNIX was based upon SVR3.2, as was ISC 386/ix. Among the more obscure distributions of SVR3.2 for the 386 were ESIX 3.2 by Everex and "System V, Release 3.2" sold by Intel themselves; these two shipped "plain vanilla" AT&T's codebase.[13] IBM's AIX operating system is an SVR3 derivative." https://en.wikipedia.org/wiki/Xenix https://en.wikipedia.org/wiki/Xenix >"In 1987, SCO ported XENIX to the 386 processor, a 32-bit chip, after securing knowledge from Microsoft insiders that Microsoft was no longer developing XENIX.[40] XENIX System V Release 2.3.1 introduced support for i386, SCSI and TCP/IP. SCO's XENIX System V/386 was the first 32-bit operating system available on the market for the x86 CPU architecture. [...] SCO released its SCO UNIX as a higher-end product, based on System V R3 and offering a number of technical advances over XENIX; XENIX remained in the product line. In the meantime, AT&T and Sun Microsystems completed the merge of XENIX, BSD, SunOS and System V R3 into System V R4. The last version of SCO XENIX/386 itself was System V R2.3.4, released in 1991.[45]"