The AS400 and IBM i Knowledge Base for the IBM Power Era
Clear answers about AS400, IBM i, iSeries, System i, and modern IBM Power systems ... from legacy terminology to Power11 upgrade planning.
AS400 Is Still How the World Searches for IBM i
AS400 is legacy terminology, but it is still how many IT professionals, executives, and administrators search for IBM i and IBM Power systems. The name changed over time. The business workloads did not disappear.
This site explains the full path from AS400 to IBM i, from iSeries to IBM Power, and from legacy environments to modern Power11 infrastructure ... without jargon or sales pressure.
Knowledge Hubs
AS400 Learning Center
Foundational answers about the AS400 platform ... what it is, why it persists, and how it connects to modern IBM i and IBM Power systems.
IBM i Knowledge Base
IBM i is the operating system that runs on IBM Power Systems. This section covers how it works, how it's licensed, its roadmap, and what IBM i support looks like today.
IBM Power Hardware Center
IBM Power Systems are the hardware platform that runs IBM i workloads today. This section covers Power9, Power10, and Power11 hardware, model history, and how to evaluate your current environment.
Power11 Upgrade Hub
IBM Power11 is the current generation of IBM Power Systems, released in 2024. This section covers Power11 specs, pricing, and upgrade paths from Power9 and Power10 environments.
AS400 Modernization Center
AS400 modernization does not always mean migration. This section covers green screen modernization, API enablement, cloud integration, and when it makes sense to stay on IBM i.
Tools and Resources
Quick-reference tools for IBM i and AS400 administrators and evaluators: terminology glossary, IBM i version timelines, CPW charts, end-of-support dates, and upgrade checklists.
Start Here
The most common AS400 and IBM i questions, answered.
Definitions for AS400, IBM i, RPG, CPW, DB2 for i, and all related terminology.
Browse the AS400 Glossary →Planning an AS400 upgrade or Power11 migration? Midland Information Systems can help.
Talk with a Specialist →Still Running IBM i Workloads?
Learn how AS400-era environments map to modern IBM Power systems and when a Power11 upgrade makes sense for your organization.
Recent Articles
AS400 vs IBM i
AS400 is a hardware brand name from 1988. IBM i is the current official name for the operating system that runs on IBM Power hardware. They are the same lineage, different names. Understanding the distinction matters for licensing, support conversations, and upgrade planning.
Read →IBM Power11 Overview
IBM Power11 is the latest generation of IBM Power Systems hardware, released in 2024. Power11 delivers new performance gains, energy efficiency improvements, and full compatibility with IBM i workloads from AS400-era applications forward.
Read →Is AS400 Still Used?
Yes. AS400 ... now called IBM i on IBM Power Systems ... is still actively used by thousands of organizations worldwide. IBM continues to invest in the platform with new hardware releases and OS updates.
Read →What Is AS400?
AS400 is IBM's mid-range business computing platform introduced in 1988. Despite multiple name changes over the decades, AS400 remains the most widely used search term for IBM i, iSeries, and IBM Power systems worldwide.
Read →What Replaced AS400?
IBM i on IBM Power Systems hardware replaced the AS400. The operating system evolved through iSeries, System i, and IBM i naming. IBM Power10 and Power11 are the current hardware generation. The workloads never disappeared ... only the brand names changed.
Read →Need Help with Your IBM i Environment?
Midland Information Systems specializes in IBM Power systems, AS400 upgrades, and IBM i support for organizations of all sizes.