Z/OS
< Z
| Developer | IBM |
|---|---|
| Written in | primarily PL/X, HLASM, and C/C++ |
| OS family | |
| Working state | Current |
| Source model | Closed source with open source components |
| Initial release | March 30, 2001 (V1R1, announced October, 2000) |
| Latest release | Version 3.1 (V3R1) / September 29, 2023 |
| Marketing target | Enterprise / Mainframes |
| Available in | English and other languages |
| Package manager | SMP/E |
| Platforms | z/Architecture |
| Kernel type | Monolithic (uniquely hardware-assisted) |
| Userland | MVS, UNIX System Services |
| Default user interface | ISPF, z/OS Management Facility |
| License | Proprietary monthly license charge (MLC); pricing available based on actual use (VWLC, EWLC, AWLC, EAWLC, IWP); reduced pricing options (zELC, zNALC, "Solution Edition") for many applications |
| Official website | ibm |
| History of IBM mainframe operating systems |
|---|
z/OS is a 64-bit operating system for IBM z/Architecture mainframes, introduced by IBM in October 2000. It derives from and is the successor to OS/390, which in turn was preceded by a string of MVS versions. Like OS/390, z/OS combines a number of formerly separate, related products, some of which are still optional. z/OS has the attributes of modern operating systems but also retains much of the older functionality that originated in the 1960s and is still in regular use—z/OS is designed for backward compatibility.