IBM OS/2 Warp Version 4 Artwork

25 years ago—on September 26, 1996—IBM launched OS/2 Warp Version 4, its last major attempt to compete with Microsoft Windows in desktop operating systems. While a competent and highly regarded OS, it didn’t take the OS crown. Here’s a look at why Warp 4 was special—and how it lives on in unexpected ways.

OS/2: IBM’s Alternative to Windows

IBM OS/2 is a computer operating system that originated in 1987 as a successor of IBM PC-DOS (also known as MS-DOS when released by its developer, Microsoft). OS/2 began as a partnership between IBM and Microsoft, but the pair split up around 1990 after the release of Windows 3.0—the two companies wanted to go in different directions. In the years following, OS/2 grew in sophistication while competing head-to-head with Microsoft for control of the PC-operating system space.

The OS/2 Warp 4 default desktop on first boot.

In 1994, IBM released OS/2 Warp (version 3), its first major version of OS/2 developed after its partnership with Microsoft imploded, with IBM developers doing the heavy lifting on the development front. As a result, OS/2 Warp 3 included a distinctive flavor to its interface while introducing internet features and maintaining rock-solid stability and backward compatibility with MS-DOS and Windows 3.x programs.

With the launch of OS/2 Warp 3, IBM made a huge marketing push in a strong attempt to unseat Microsoft’s control of the PC-operating system market. Depending on who you ask, Warp didn’t catch on due to expensive requirements for developers, limited hardware support,ย monopolistic tricks from Microsoft, or IBM’s marketing blunders. Windows was also an entrenched standard with a relatively low cost, wide hardware support, and plenty of developers on its side.


All that being said, OS/2 Warp won its share of die-hard fans, and when IBM released OS/2 Warp Version 4 in 1996, they found a mature, stable, fully featured 32-bit operating system that could easily hold its own against Windows 95, and the fact that Microsoft won anyway with “inferior” technology was one of the most frustrating tech tales of the 1990s.

IBM OS/2 Warp 4 Retail Box Cover
The front of the OS/2 Warp 4 retail box. IBM

At launch, OS/2 Warp 4 retailed for $249 or $149 for an upgrade (that’s about $431 and $258 when adjusted to today’s dollars). That was more expensive than Windows 95’s retail price of $209.95 at launch, but it was still competitive for a consumer OS at the time.

RELATED: Windows 95 Turns 25: When Windows Went Mainstream

OS/2 Warp 4 Requirements and Features

IBM released OS/2 Warp 4 in several different configurations, including a consumer version and a server version (“OS/2 Warp Server”) designed largely for hosting local area networks. The regular Warp Version 4 required a 33 MHz Intel 486 CPU or higher (but IBM recommended a Pentium 100 for its voice navigation features), 12-16 MB of memory, and a video card that could display 640×480 with 256 colors.

IBM OS/2 Warp 4 Box Illustration

Among Warp 4’s many new features, IBM most often touted the following in its marketing and advertising materials.

  • VoiceType: A voice recognition and dictation system that allows speed-to-text input and voice navigation of the OS. For example, you can tell OS/2 to “go to sleep” to put your PC to sleep or “open games” to open your games folder. With training, it can recognize over 70,000 words and can potentially replace typing with a keyboard—if you’re patient enough.
  • Java Integration: Warp 4 includes a fully integrated Java virtual machine that allowed you to run Java programs directly from OS/2’s Workplace Shell without a browser. That was pretty cutting-edge in 1996.
  • WarpCenter: Similar to Windows 95’s taskbar, OS/2 Warp 4 includes WarpCenter, a toolbar (based on Lotus SmartCenter) positioned at the top or bottom of the screen that can manage tasks and launch apps. Special containers called “trays” can hold app or document shortcuts and file system locations for easy access.
  • WarpGuide: For helping users through complex OS operations, IBM introduced WarpGuide, an interactive help system that turned dialog boxes into a multi-step color-coded process that was intended to make things more user-friendly. Whether IBM succeeded or just made things more confusing in the process is up for debate.
  • OpenDoc Support: For a time, Apple, Motorola, and IBM hyped the OpenDoc software framework as a better way to make document-centric applications using components rather than monolithic applications. OpenDoc is, frankly, an inscrutable concept to anyone outside of software development, which is likely one of the reasons it failed and Apple abandoned work on it in 1997. IBM OS/2 Warp 4 supported OpenDoc, but never for any useful purpose.

Some other minor features touted on the back of the OS/2 Warp 4 retail box include support for OpenGL (the 2D/3D graphics API) and TrueType fonts, Lotus Notes Mail (a messaging system), the inclusion of the IBM WebExplorer browser, and access to Netscape Navigator for OS/2 (a free download).

OS/2 Warp 4 Facts and Trivia

IBM OS/2 Warp 4 running Mahjongg Solitaire.
OS/2 Warp 4 running IBM’s Mahjongg Solitaire.

Compared to Windows or macOS that many people are familiar with, OS/2 Warp 4 seems a little quirky. Here are some unique and interesting bits of info and trivia about the OS.

  • Like previous versions of OS/2, Warp 4 could run 16-bit Windows 3.x apps through a special environment called “Win-OS/2” that ran inside a window within OS/2. When run, you see a Windows 3.x like environment with Program Manager and basic Windows apps licensed from Microsoft.
  • Certain early copies of Warp 4 included a microphone headset for use with OS/2’s VoiceType speech recognition software.
  • During development, OS/2 Warp 4’s code name was “Merlin.”
  • OS/2 calls its shortcuts “shadows,” which are similar to shortcuts in Windows or aliases on macOS but slightly different because they aren’t file system objects.
  • Instead of a trash can or recycle bin, OS/2 Warp 4 includes a “Shredder” on the desktop for deleting files. It features an icon of an office paper shredder.
  • Warp 4 included three built-in games: Mahjongg Solitaire (tile matching), Klondike Solitaire, and OS/2 Chess.

OS/2’s Legacy

OS/2 Warp 4 received generally great reviews from the computer press at launch, but it didn’t turn the tide against Microsoft’s lock on the PC operating system market. Still, IBM continued to sell Warp 4 and Warp Server until December 23, 2005, releasing patches (called “Fix Packs”) for it along the way. IBM’s customer support for OS/2 officially ended on December 31, 2006. In a sign of just how bitter the Microsoft/IBM OS feud had become, IBM encouraged vendors to switch to Linux instead of Windows when choosing a path away from OS/2.


Due to its stability, vendors used OS/2 Warp 4 frequently for embedded applications (such as bank ATMs) where a crash would be embarrassing or costly. By the mid-2000s, more stable versions of Windows began to catch up with OS/2’s installed base for embedded applications. Some ATMs likely still run OS/2 or one of its licensed derivatives such as eComStation and ArcaOS today. As late as 2019, the New York subway system still used OS/2 because of its stability and the cost of migrating to a new system.

A screenshot of the OS/2-based eComStation OS from 2002. eComStation

Another advantage of the latest OS/2 derivatives is that they can run multiple instances of legacy DOS or Windows programs (16 or 32-bit) each in their own sandboxed instance, side-by-side, so if one app crashes, it won’t take down the whole system. So it’s likely that even though most people consider OS/2 a dead OS, it will likely still be powering important industrial, commercial, and embedded systems for decades to come. If it ain’t broke, why fix it?

Happy birthday, Warp 4!

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Benj Edwards is an Associate Editor for How-To Geek. For over 15 years, he has written about technology and tech history for sites such as The Atlantic, Fast Company, PCMag, PCWorld, Macworld, Ars Technica, and Wired. In 2005, he created Vintage Computing and Gaming, a blog devoted to tech history. He also created The Culture of Tech podcast and regularly contributes to the Retronauts retrogaming podcast.
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