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IBM i.png
OS familyIBM i
Working stateCurrent
Source modelClosed source
Initial releaseApril 2, 2008; 12 years ago (2008-04-02)
Latest release7.4 / April 23, 2019; 18 months ago (2019-04-23)
Marketing targetMinicomputer and enterprise server
Available inEnglish
PlatformsIBM Power Systems
Kernel typeshares many Microkernel (SLIC) and Virtual machine (TIMI) design philosophies
Preceded byi5/OS, OS/400, System/36, System/38
Official websiteIBM i

IBM i is an integrated operating environment developed by IBM, consisting of operating system, database, middleware, and development tools.[1] IBM i runs on IBM Power Systems servers,[2] as do IBM AIX[3] and Enterprise Linux.[4]

It replaced the i5/OS and OS/400 operating systems but maintains application compatibility with both.[5]


IBM designed IBM i as a "turnkey" operating system, requiring little or no on-site attention from IT staff during normal operation. As such, it has been described as "the driverless variant of IT infrastructure."[6] For example, IBM i has a built-in Db2 database which does not require separate installation. Mass storage ("disks") can be RAIDed or mirrored; when either of those options is configured, one or more disks can be replaced without interrupting work. System administration is wizard-driven. Automatic self-care can schedule all common system maintenance, detect many failures and order spare parts and service automatically. Organizations using IBM i sometimes have a pleasant sticker shock when comparing the overhead of cost of system maintenance on other systems.[7] The overall total cost of ownership (TCO) for IBM i on IBM Power Systems is dramatically lower than two competing platforms, like Windows/SQL Server and Linux/Oracle, primarily due to the lack of system management personnel needed; integrated components also lower the TCO.[8]

IBM i programs, like System/38 programs before them, contain both processor-independent "virtual" binary code and processor-dependent executable binary code. Compilers for IBM i produce the processor-independent code as their output; the operating system automatically translates the processor-independent code into the processor-dependent code as needed, without the need for source code or attention by IT personnel. Notably, when migrating from a legacy processor (for example, from CISC to RISC hardware), if automatic migration is configured and if the original program was created with normal options, the system will rebuild the executable code automatically and in just a few seconds. Migration consists of taking a backup from the old computer, and restoring it on the new.[7]

The system was one of the earliest to be object-based. Unlike traditional operating systems like Unix and Windows NT there are no files, only objects of different types. The objects persist in very large, flat virtual memory, called a single-level store.[7]

IBM i offers an upgrade path so that application software written for previous operating systems on IBM System i can be migrated to current supported hardware without needing to be modified or recompiled. To do so, it provides an abstract interface to the hardware via layers of low-level machine interface code (MI) or Microcode that reside above the Technology Independent Machine Interface (TIMI) and the System Licensed Internal Code (SLIC) or kernel.[5]

IBM i includes numerous software technologies[9]

Application development

IBM Portable Application Solutions Environment for i (PASE for i) enables port of IBM AIX applications to the IBM i platform.[10] PASE for i provides an integrated AIX runtime environment on the IBM i, including three industry-standard and defacto-standard shells (ksh, sh, and csh) and utilities for a powerful scripting environment, enabling many AIX applications to run on the IBM i operating system with little or no change. AIX programs are binary compatible with IBM i when using PASE. PASE is essentially "an operating system within an operating system", supporting the most recent stable version of AIX. Many AIX 5L compatible binaries may be executed without modification or recompilation in the PASE environment. Exceptions to this are programs that contain direct calls to AIX kernel based APIs as there is no AIX kernel in PASE. Programs can be built directly in place with the GNU Compiler Collection (GCC), or alternatively with the IBM XL C/C++ compilers. Support is provided for running both 32-bit and 64-bit AIX executables.

Integrated Web Services for i enables Integrated Language Environment (ILE) applications to perform in the web services and service-oriented architecture (SOA) arena.[11]

Net.Data for i is a server-side scripting language that extends web servers by enabling the dynamic generation of web pages.[12]

IBM InfoSphere Data Architect is a collaborative enterprise data modeling and design solution.[13]

Management interfaces

IBM Navigator for i is a web-based interface to a family of products providing a comprehensive set of system management, performance analysis, database, Apache web server, and WebSphere Application Server features for IBM i.[14]

IBM i Access Client Solutions is a Java-based client and a user, development and systems management interface solution that runs on Linux, macOS and Windows to provide 5250 emulation to run host applications. The Web-based IBM i Access Client solution enables desktop and mobile device users to connect to IBM i via web browsers.[15]

Networking and communications

TCP/IP on IBM i offers TCP/IP applications, protocols, and services to direct the flow of data in and out of the network.[16]

Open-source software

Open-source software available includes Apache HTTP Server, OpenSSL, Java, Ruby, PHP, Python, Node.js, gcc, Nginx, Git, and hundreds of other packages.[17] In 2018, IBM made available the Yum package manager and the capability to install open-source software via RPM packages.[18][19] Formal support for many packages is available from IBM and partners.[20]

Programming languages

The OS supports many languages: RPG, assembly language, C, C++, Pascal, Java, EGL, Perl, Smalltalk, COBOL, SQL, BASIC, PHP, PL/I, Python, REXX, Ruby, PHP, Node.js(JavaScript), Lua, R, Ublu,[21]Qshell, and more.

Development tools

IBM Rational Developer for i is the integrated development environment (IDE) published by IBM for working with many technologies such as RPG. Industry-standard tools can be used for programming as well, and are especially popular when using open source languages. Several other tools are available from independent software vendors, many of which are listed in the IBM Global Solutions Directory.

IBM i history and versions

IBM i release 6.1 was announced April 2, 2008 with IBM POWER Systems.[22] This release numbering contrasts with previous version identifier format VxRxMx (Version, Release, Modification, e.g. V5R4M0) of prior versions in its lineage. This release number demonstrated the ability for applications built on previous technologies to continue their functional usage on the new Power Systems technology.

With 7.1, IBM started delivering more updates to the operating system via Technology Refreshes. These Technology Refreshes enable further value to the operating system without the need of incurring point releases and allowing customers longer periods between upgrades. For 7.1, Technology Refresh 11 was released in October 2015. IBM i 7.2 Technology Refresh 9 was released in September 2018. IBM i 7.3 Technology Refresh 6 was released May 10, 2019.[23]

Version 7.2 was released in May 2014.[24]

Version 7.3 was released in April 2016.[25]

The latest version of IBM i is 7.4, announced on April 23, 2019 and released on June 21, 2019 (Version Support Schedule).

Every release of IBM i has a finite support period.[26][27]

IBM i versions

Version[28] Release date[29] End of Program
Old version, no longer maintained: 6.1 2008-03-21 2015-09-30 IBM i 6.1 Documentation
Old version, no longer maintained: 7.1 2010-04-23 2018-04-30 IBM i 7.1 Documentation
Older version, yet still maintained: 7.2 2014-11-11 2021-04-30 IBM i 7.2 Documentation
Older version, yet still maintained: 7.3 2016-04-15 TBA IBM i 7.3 Documentation
Current stable version: 7.4 2019-06-21 TBA IBM i 7.4 Documentation
Old version
Older version, still maintained
Latest version
Latest preview version
Future release

Lineage of previous technology (CPF, OS/400 and i5/OS) and versions

As IBM i supports running legacy applications built for CPF on System/38, OS/400 on AS/400, or i5/OS on iSeries respectively), the lineage of the platform is often associated with those technologies as well.

In 1978, the fundamental architectural principles of what would become IBM i operating system were introduced with CPF operating system for the IBM System/38, developed by IBM team in Rochester, Minnesota, led by IBM chief scientist Frank Soltis, (pages xxvi-xxvii of *Soltis, Frank G. (2001). Fortress Rochester: the Inside Story of the IBM iSeries, NEWS/400 Books. ISBN 1-58304-083-8

In 1988, OS/400 Release 1 drew upon and extended the heritage of CPF to power the Application System/400 (AS/400) line of midrange computers.

For the period 1988-2006, OS/400 versions 1 through V5R3 were released as AS/400 underwent rebranding to Advanced System/400 and IBM eServer.[32][33]

In 1999, IBM introduced logical partitioning (LPARs) with i5/OS to support multiple virtual systems on a single hardware footprint.

In 2006, the operating system at V5R4 was named i5/OS for the newly introduced System i servers, which IBM marketed until 2008.

Version[28] Release date[29] End of Program
Old version, no longer maintained: V1 1988-08-26 1993-05-31
Old version, no longer maintained: V2R1 1991-05-24 1994-06-30
Old version, no longer maintained: V2R1M1 1992-03-06 1994-06-30
Old version, no longer maintained: V2R2 1992-12-18 1995-06-30
Old version, no longer maintained: V2R3 1993-12-17 1996-05-31
Old version, no longer maintained: V3R1 1995-06-21 1998-10-31
Old version, no longer maintained: V3R2 1996-06-04 2000-05-31
Old version, no longer maintained: V3R6 1995-12-22 1998-10-31
Old version, no longer maintained: V3R7 1996-11-08 1999-06-30
Old version, no longer maintained: V4R1 1997-08-29 2000-05-31
Old version, no longer maintained: V4R2 1998-02-27 2000-05-31
Old version, no longer maintained: V4R3 1998-09-11 2001-01-31
Old version, no longer maintained: V4R4 1999-05-21 2001-05-31
Old version, no longer maintained: V4R5 2000-07-28 2002-12-31
Old version, no longer maintained: V5R1 2001-05-25 2005-09-30
Old version, no longer maintained: V5R2 2002-08-30 2007-04-30
Old version, no longer maintained: V5R3 2004-06-03 2009-04-30 V5R3 Documentation
Old version, no longer maintained: V5R4 2007-04-20 2013-09-30 V5R4 Documentation
Old version
Older version, still maintained
Latest version
Latest preview version
Future release

See also

User groups

User groups have played a major part in the evolution of IBM i. COMMON is the world's largest professional association of IBM technology users. It provides independent education, certification, advocacy and networking among users, IBM and related third-party solution providers.[34] The Large User Group (LUG),[35] whose membership consists of major corporations, is a major influence for current and future development of IBM i. Both COMMON and LUG work with IBM regularly to help provide constructive feedback and perspective to IBM i platform direction. The Young i Professionals (YIPS)[36] is a subset of COMMON that has been significant in influencing the direction of the IBM i.


  1. ^ "IBM i: A platform for innovators, by innovators". International Business Machines. Retrieved 2020.
  2. ^ "Operating Systems". International Business Machines. Retrieved 2020.
  3. ^ "IBM AIX". IBM. Retrieved 2020.
  4. ^ "Enterprise Linux". IBM. IBM. Retrieved 2020.
  5. ^ a b Will, Steve. "Steve Will talks IBM I in 2019". Helpsystems. Retrieved 2020.
  6. ^ "IBM i - The driverless variant of IT infrastructure". IBM IT Infrastructure. 2019-08-13. Retrieved .
  7. ^ a b c Soltis, Frank, "Inside the AS/400"; Frank Soltis was the AS/400 system architect.
  8. ^ "IBM i's TCO Advantage Widens, According to Reports". IT Jungle.
  9. ^ "IBM software technologies". IBM. Retrieved 2020.
  10. ^ "IBM PASE for i". IBM. Retrieved 2020.
  11. ^ "Integrated Web Services for i". Retrieved 2020.
  12. ^ "Net.Data for i". IBM. Retrieved 2020.
  13. ^ "InfoSphere® Data Architect". IBM. Retrieved 2020.
  14. ^ "IBM Navigatore for i". IBM. Retrieved 2020.
  15. ^ "IBM I Access Client Solutions". IBM. Retrieved 2020.
  16. ^ "TCP/IP". IBM. Retrieved 2020.
  17. ^ "IBM i Open Source using yum". IBM i Open Source.
  18. ^ "Open Source Has Never Tasted So Good!". IBM Systems Magazine - Open Your i.
  19. ^ "IBM i Open Source using yum". IBM i Open Source.
  20. ^ "Open Source Support for IBM i". 2019-05-30. Retrieved .
  21. ^ Ublu
  22. ^ IBM Introduces the First in a New Generation of Power Systems
  23. ^ "IBM i Technology Refresh". IBM.
  24. ^ "Planned Availability Date". IBM i 7.2 TR3 and IBM i 7.1 TR11 offer performance, usability, and integration enhancements.
  25. ^ "IBM i 7.3". IBM i 7.3 can deliver significant client value for database and security, and support for industry-leading workloads like analytics and mobile computing.
  26. ^ "IBM i Release Support". IBM Support.
  27. ^ "Release life cycle". IBM Support.
  28. ^ a b IBM i Technology Updates
  29. ^ a b IBM i Software lifecycle
  30. ^ a b IBM i Upgrade planning:Releases
  31. ^ a b IBM i Documentation:Releases
  32. ^ "OS 400 - Complete History of the IBM OS/400". history-computer.
  33. ^ "History of OS/400".
  34. ^ "COMMON". COMMON. Retrieved .
  35. ^ "LUG". LUG. Retrieved 2019.
  36. ^ "Young i Professionals (YIPS)". YIPS. Retrieved .

External links

  This article uses material from the Wikipedia page available here. It is released under the Creative Commons Attribution-Share-Alike License 3.0.



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