How AS400 Software Is Different from IBMi?

Due to several name changes, confusion has persisted that AS400 and IBMi are the same things. And this confusion between AS400 software and IBMi has been a significant growth obstacle for enterprises in the market considering IBM technology. Both are like two different fruits or in technical terms, it’s like comparing hardware to software. AS400 software is the physical server developed by IBM in the 1980s, and IBMi is the latest OS for today’s version of AS400, i.e., IBM Power Systems.

The IBM iSeries software running on the operating system/400 has a long history. And with the long history come several terms and terminology that tend to be “sticky.” And the event is not uncommon. Most of us have minicomputers in our pockets that we call smartphones, though today’s phones hold little similarity to the old generation stationary rotary phone. Today we might call electrical burners stoves, but they have gone through a total evolutionary in those decades and reached here from the original cast-iron stoves. But we still use and misuse (sometimes) the names of several products in our daily life.

Similar is the case with AS400 software and IBMi. Even in the IT sector, many people believe that these are two different iterations of the same technology. But the truth is that they refer to very other things, which has caused a lot of confusion. This confusion between as400 software and iSeries software has been a falling block to digital transformation for enterprises in the market considering IBM technology.

What is AS400 Software?

AS400 software is also known as System i, iSeries, and Application System 400. The application server is commonly known as AS400, and it is a mid-range server designed by IBM, for small, medium, and large enterprises.

IBMi vs AS400: Why both cannot be compared?

Long story short, comparing AS400 software with IBMi is like comparing apples with oranges-or more accurate definition, comparing hardware to software. To understand more, you need to know a little bit about the history of what is AS400 software. This will clear the confusion.

IBM introduced the AS400 software or application server/400 in the year 1988. The intention behind it is to cover the mid-range computer system primarily for small and medium-sized businesses. At that time, it came to its operating system, i.e., OS/400.

In the past three decades, the AS400 software evolved multiple times. First, it became the iSeries and was eventually renamed “System i.” So, now the machine is referred to as IBM iSeries, which means it is one of the latest avatars of the original AS400. Currently, the setup is known as “IBM Power Systems” and “Power Series.”

The operating system for Power Series is IBM I, and it’s the grandchild of OS/400, which went through many iterations. In a nutshell, AS400 software is the physical server from the 1980s, and IBM i is the latest OS for Power Systems, i.e. today’s version of AS400.

People say that the IBM Power Series is an “embodiment” of the AS400 software. IBM tried very hard to develop all its operating systems and hardware, compatible with the modern trend. Applications written initially for the AS400 and running on OS/400 can work on today’s machines. And this is the strength of IBM Power Systems. But it also means that specific ways of talking about technology exist, even if the technology changes.

Significantly, people who have worked with IBM technology in the past are comfortable speaking about the applications written for AS400. And the people who have joined this technology field later talk about the application written for IBM I, particularly when discussing the application should run on a public cloud or hybrid cloud.