Leverage a highly secure and scalable operating system for running mission-critical applications
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IBM z/OS® is an operating system (OS) for IBM Z® mainframes, suitable for continuous, high-volume operation with high security and stability.

With IBM z/OS, you can bring the computing power and resources of the IBM Z platform to help drive business transformation and accelerate innovation. Get the stable, secure environment your organization requires to improve performance for mission-critical workloads and meet future challenges.

IBM z/OS 3.1 marks a new era in OS intelligence. The new version of z/OS allows you to:

  • Scale the value of data and drive digital transformation powered by AI and intelligent automation
  • Protect and thrive with exceptional cyber resilience capabilities
  • Manage and optimize technology infrastructure with intuitive interfaces 
  • Build new and modernize existing applications with a flexible hybrid cloud strategy
Get more details on z/OS 3.1
IBM announces watsonx Code Assistant for Z

IBM extends generative AI-powered watsonx Code Assistant to accelerate mainframe application modernization.

Data sheet: Deep dive into the product details for IBM z/OS

Explore past z/OS announcements

Benefits AI-infused

Scale the value of data and drive digital transformation powered by AI and intelligent automation.

Application modernization and simplification

Build new applications or modernize existing ones while optimizing and simplifying technology infrastructure.

Cyber resiliency

Protect and thrive with unparalleled security and resilience capabilities with quantum-safe technologies.

Featured capabilities Simplified management

Improve z/OS programmer productivity with a web-based interface and streamlined, automated tasks.

Explore z/OS Management Facility
Upgrade workflows

Enable and drive innovative development to support new hybrid cloud and AI business applications.

Explore z/OS Upgrade Workflows
Linux integration

Integrate popular open-source packages, Linux® applications, IBM software and third-party software.

Explore IBM z/OS Container Extensions
Cloud provisioning

Simply create software service templates that provision IBM middleware for additional functionality.

Explore IBM Cloud® Provisioning for z/OS
JSON databases

Easily create and access JSON databases through a comprehensive set of C-based APIs.

Explore EzNoSQL for z/OS
Management services

Deploy services that streamline management tasks and apply best practices and internal standards.

Explore z/OS Management Services Catalog
Faster recovery

Restore services and recover workloads substantially faster with zero increase in licensing costs. 

Explore IBM System Recovery Boost
IT resilience

Rapidly adapt and respond to disruptions or threats and continue operations without significant impact.

Explore IBM zSystems Resilience
Pervasive encryption

Enable extensive encryption of data in-flight and at-rest to safeguard data and achieve compliance.

Explore IBM zSystems Pervasive Encryption
Simplified data archiving

Use serverless data movement and storage cloud communication to simplify data archiving in the cloud.

Explore transparent cloud tiering
Server communications

Run multiple copies of z/OS as a single image, so you can manage multiple systems and resources from a single point of control.

Explore Parallel Sysplex
Supporting capabilities Workflow automation

Orchestrate configuration management, application deployment and provisioning IT tasks on z/OS.

Explore z/OSMF Ansible Collection
Container images

Download open-source, no-cost container images that can run in Linux and zCX environments of z/OS.

Explore IBM zSystems and LinuxONE Container Registry

Jump-start or accelerate application modernization and take a standardized approach to IT automation.

Explore IBM zSystems and Cloud Modernization Stack
Resources z/OS data sheet

Take a deep dive into the product details for IBM z/OS.


Explore some of the most frequently asked questions about z/OS V2.5.

z/OS language environment concepts guide

Read the guide to learn how to run C, C++, COBOL, PL/I Fortran and assembler apps.

Getting started with IBM z/OS Container Extensions (zCX)

Learn more about installing, tailoring and configuring zCX in your own environment.

Demystify data

Investigate why IBM Z is the ideal AI platform for solving user pain points.

Getting started with encryption

Understand how hardware and software components interact within a z/OS data set encryption environment.

What’s new in DFSMSrmm

See the latest enhancements to this fully functioning tape management system for removable media.

Getting started with zHyperLink

Find out how IBM zHyperLink for IBM z/OS makes it easy to accelerate transaction processing for the mainframe.

Getting started with IBM Z resiliency

Discover how hardware components and software components interact in a z/OS data set encryption environment.

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