virtual machine

(redirected from Virtual platform)
Also found in: Dictionary.

virtual machine

[′vər·chə·wəl mə′shēn]
(computer science)
A portion of a computer system or of a computer's time that is controlled by an operating system and functions as though it were a complete system, although in reality the computer is shared with other independent operating systems.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

Virtual Machine

(operating system)
(VM) An IBM pseudo-operating system hypervisor running on IBM 370, ESA and IBM 390 architecture computers.

VM comprises CP (Control Program) and CMS (Conversational Monitor System) providing Hypervisor and personal computing environments respectively. VM became most used in the early 1980s as a Hypervisor for multiple DOS/VS and DOS/VSE systems and as IBM's internal operating system of choice. It declined rapidly following widespread adoption of the IBM PC and hardware partitioning in microcode on IBM mainframes after the IBM 3090.

VM has been known as VM/SP (System Product, the successor to CP/67), VM/XA, and currently as VM/ESA (Enterprise Systems Architecture). VM/ESA is still in used in 1999, featuring a web interface, Java, and DB2. It is still a major IBM operating system.

["History of VM"(?), Melinda Varian, Princeton University].

virtual machine

An abstract machine for which an interpreter exists. Virtual machines are often used in the implementation of portable executors for high-level languages. The HLL is compiled into code for the virtual machine (an intermediate language) which is then executed by an interpreter written in assembly language or some other portable language like C.

Examples are Core War, Java Virtual Machine, OCODE, OS/2, POPLOG, Portable Scheme Interpreter, Portable Standard Lisp, Parallel Virtual Machine, Sequential Parlog Machine, SNOBOL Implementation Language, SODA, Smalltalk.

virtual machine

A software emulation of a physical computing environment.

The term gave rise to the name of IBM's VM operating system whose task is to provide one or more simultaneous execution environments in which operating systems or other programs may execute as though they were running "on the bare iron", that is, without an eveloping Control Program. A major use of VM is the running of both outdated and current versions of the same operating system on a single CPU complex for the purpose of system migration, thereby obviating the need for a second processor.
This article is provided by FOLDOC - Free Online Dictionary of Computing (

virtual machine

(1) The name of various language interpreters. See Java Virtual Machine and Python.

(2) A virtual machine (VM) is an operating system and one or more apps running in an isolated partition within the computer. Depending on the size of the hardware, any number of VMs can be running. The more CPU cores, the more simultaneity (see multicore). For example, when cloud computing servers are used, it is one or more virtual machines that the customer is actually renting (see cloud computing).

Dating back to the 1960s, virtual machines (VMs) are widely used to run multiple instances of the same OS, each running a different set of applications. The separate instances prevent apps from interfering with one another after a crash, especially when testing new software. Virtual machines are also widely used to run different operating systems in the same machine. For example, a Mac running Windows alongside macOS is creating a virtual environment for Windows.

Not Dual Boot or Multiboot
Virtual machines differ from a dual-boot or multiboot setup, whereby the user has to choose from a menu which OS to use at startup (see dual-boot). A virtual machine (VM) contains an OS and applications, and any changes require a reconfiguration of the software in the VM.

Non-Virtual Versus Virtual
The OS in each VM is a "guest operating system" that communicates with the hardware via the VM monitor. The guest OS may be the same or different. "Virtualization" is commonplace today. See virtual machine monitor, virtualization and paravirtualization.

Advantages of Virtualization

#1 - Consolidation
Multiple operating systems can run in the same server, eliminating the need to dedicate a single machine to each OS. New OS versions can be deployed and tested without adding hardware. In the datacenter, multicore servers with many threads of execution save space and power.

#2 - Stability and Security
Troubleshooting can be daunting when conflicts arise in supposedly stable apps. Prior to virtualization, cautious system administrators hosted each type of application in a separate server even if grossly underutilized. However, VMs are isolated from each other, and a security breach in one does not affect the others.

#3 - Development Flexibility
A virtualized computer can host numerous versions of an operating system, allowing developers to test their programs in different OS environments on the same machine.

#4 - Migration and Cloning
Virtual machines function like self-contained packages that are said to be "decoupled from the hardware." It is relatively easy to move a VM instance from one server to another to balance the workload, migrate to faster hardware or to recover from hardware failure.

#5 - Desktop Virtualization
Another virtualization trend is storing a user's OS and apps in a VM in the server and use the PC as a "thin client" to that VM. Each user is isolated from all others, and maintenance is shifted from the user's computer to the datacenter (see thin client). See virtual machine monitor, virtualization, application virtualization and OS virtualization.
Copyright © 1981-2019 by The Computer Language Company Inc. All Rights reserved. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction is strictly prohibited without permission from the publisher.
References in periodicals archive ?
The challenges facing youth entrepreneurs in Africa are broad and varied, and this was precisely the reason why the United Nations Development Programme (UNDP) decided to establish a virtual platform for entrepreneurs.
Citing exponential growth of social media users in Bhutan and the very nature of the virtual platform, the Election Commission of Bhutan (ECB) has admitted that monitoring posts related to the elections will be a daunting task.
But as states, corporations and even society goes to a virtual platform through social media, one must not hinder their creativity and hard work through dogma.
This year-long campaign provides a unique opportunity for participants to become more capable and skillful investors by Learning, Engaging, Practicing, and Competing in a virtual platform that provides a real life experience of actual trading in the stock market.
Wecast Network has a focus on 'BASE' technology and infrastructure (blockchain, artificial intelligence, supply chain and exchanges) to power V PaaS (Virtual Platform as a Service).
ESDS then incorporated its R&D Team in 2009 with an aim to create a scalable virtual platform to reduce the downtime & performance issues that was experienced due to sporadic loads.
Vtradefair, a virtual platform for online tradeshows and exhibitions, is proud to announce its successful completion of one year in February 2016 and is now looking to raise funds.
This new virtual platform is still very much in development at the moment and once completed will be able to work with Oculus Rift.
The virtual platform makes it easy to register, upload a resume, and learn about participating employers before the event.
This rebuild solution, based on Nutanix hardware and VMware virtual platform, provided by Proact has exceeded the expectations of Helkama Emotor.
Lebara Mobile KSA has signed an agreement with Huawei to supply a virtual platform for the operator in the Kingdom.
Dubai-based luxury hotel group Jumeirah has launched Jumeirah Inside - a virtual platform comprising 360[degrees] video and photography which enables users to make hotel bookings.

Full browser ?