VM (operating system)

Teddy bear – VM's mascot since 1983.
The default login screen on VM/370 Release 6.
CMS starting up after the user MAINT (system administrator) has logged in.
The CMS editor on VM/370, editing a COBOL program source file.
Invoking the System/360 COBOL compiler on VM/370 CMS, then loading and running the program.
An example of a non-CMS guest operating system running under VM/370: DOS/VS Release 34. The DOS/VS system is now prompting the operator to enter a supervisor name to continue loading.
OS/VS1 starting under VM/370.
Using DASD Dump/Restore (DDR) to back up a VM/370 system.

Family of IBM virtual machine operating systems used on IBM mainframes System/370, System/390, zSeries, System z and compatible systems, including the Hercules emulator for personal computers.

- VM (operating system)

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IBM System/390

Discontinued fifth generation of the System/360 instruction set architecture.

Front cover of the IBM S/390 Parallel Enterprise Server Generation 5
Front cover of the IBM S/390 Parallel Enterprise Server Generation 5
IBM S/390 Parallel Enterprise Server Gen4

The low end models were substantially less expensive than the 3090s previously needed to run MVS/ESA, and could also run VM/ESA and VSE/ESA, which IBM announced at the same time.

IBM System/370

Model range of IBM mainframe computers announced on June 30, 1970 as the successors to the System/360 family.

System/370-145 3D Rendering
3D Rendering of computer center with IBM System/370-145 and IBM 2401 tape drives
System/370-145 3D Rendering
System/370-145 system console.

four new operating systems: DOS/VS (DOS with virtual storage), OS/VS1 (OS/360 MFT with virtual storage), OS/VS2 (OS/360 MVT with virtual storage) Release 1, termed SVS (Single Virtual Storage), and Release 2, termed MVS (Multiple Virtual Storage) and planned to be available 20 months later (at the end of March 1974), and VM/370 – the re-implemented CP/CMS


The most commonly used operating system on the System/370 and System/390 IBM mainframe computers.

MVS running on the Hercules emulator

It is unrelated to IBM's other mainframe operating system lines, e.g., VSE, VM, TPF.


Programming language that can be interpreted or compiled.

Rexx is the primary scripting language in some operating systems, e.g. OS/2, MVS, VM, AmigaOS, and is also used as an internal macro language in some other software, such as SPF/PC, KEDIT, THE and the ZOC terminal emulator.


z/VM running CMS fullscreen

z/VM is the current version in IBM's VM family of virtual machine operating systems.


Series of proprietary Unix operating systems developed and sold by IBM for several of its computer platforms.

IBM RS/6000 AIX file servers used for ibm.com in the 1990s
AIX Version 4 console login prompt
Old logo
AIX PS/2 1.3 console login
AIX PS/2 1.3 AIXwindows Desktop
AIX RS/6000 servers running ibm.com in early 1998
AIX RS/6000 servers running ibm.com in early 1998
The default login banner for AIX 5.3 on PowerPC
The Common Desktop Environment, AIX's default graphical user interface
The initial menu, when running in text mode

By 1976, the operating system was in use at various academic institutions, including Princeton, where Tom Lyon and others ported it to the S/370, to run as a guest OS under VM/370.


Computer software, firmware or hardware that allows partitioning the resource of a CPU among multiple operating systems or independent programs.

Type-1 and type-2 hypervisors

The 1972 announcement also included VM/370, a reimplementation of CP/CMS for the S/370.

IBM mainframe

IBM mainframes are large computer systems produced by IBM since 1952.

IBM 704 mainframe at NACA in 1957
IBM 1401 undergoing restoration at the Computer History Museum
IBM System/360 Model 50
IBM System z800

The virtual memory capabilities also allowed the system to support virtual machines; the VM/370 hypervisor would run one or more virtual machines running either standard System/360 or System/370 operating systems or the single-user Conversational Monitor System (CMS).

Virtual machine

Virtualization/emulation of a computer system.

Logical diagram of full virtualization

This approach was pioneered in 1966 with the IBM CP-40 and CP-67, predecessors of the VM family.


Family of data management products, including database servers, developed by IBM.

IBM's first commercial relational-database product, SQL/DS, was released for the DOS/VSE and VM/CMS operating systems in 1981.