Bill Gates - "We believe that OS/2 is the platform for the 90s."

OS/2 stands for Operating System 2. IBM and Microsoft developed MS OS/2, the first version of this multi-tasking 16-bit system that was intended to replace DOS and Windows 3.x. Microsoft took part of the code to develop Windows NT 3.x. IBM continued with the development of OS/2 till 1999/2000 releasing versions 2 to 4, which are 32-bit systems. Versions 3 and 4 were released under the name OS/2 Warp. On December 23, 2005, IBM discontinued OS/2.

Many people think that the lack of interest to this OS is the result of weak North American promotion. OS/2 is more popular in Europe than in the US. Many of the sites that I visited are in Russia or Germany.

My experiences with this system are limited to OS/2 Warp 4. OS/2 has the same feeling as Windows 3.11 or Linux 1.3 with the chunky taskbar floating on the screen. OS/2 comes in two flavors blue with Windows 3.11 support and red without support. Both versions are fully compatible with DOS, allowing dual-boot. Any flavor of DOS can be installed on the machine. I recommend installing IBM) for more compatibility. Most of the shell commands are the same as the ones in DOS, for example E instead of EDIT.
 

Installing (IBM'S) Operating System 2:

You can install OS/2 over any version of DOS for a dual-boot system on any IBM compatible machine. OS/2 looks for a version of CONFIG.SYS. After installing DOS, follow the instructions on your monitor. Installing OS/2 is similar to installing Windows 3.1, putting diskette after diskette. Be patient.

For my project, I installed DOS 6.3 (also developed by IBM) and OS/2 Warp 4 (red edition, 1994) on an IBM PS/2 Model 90 machine (1993) that I had. I could have used my IBM Aptiva E26 or another machine but IBM PS/2 Model 90 was sold with OS/2 or Windows 3.11. My decision was purely sentimental.

Warp 3 was not fully year 2000 complaint. In the other hand, OS/2 Warp 4 is Y2K complaint and supports voice recognition. This version was marketed emphasizing on this issue and often used in telephony.