OS/2 has support for DOS and Windows (16 bit) built in. Most DOS programs (except those that require direct access to the system hardware) can be run, each in their own separate DOS virtual machine. 16 bit windows programs can be run either in a single windows session by running windows under OS/2 or they can be run directly in separate sessions with a separate copy of windows being started behind the scenes for each individual program.
OS/2 also has the capability of running any 16 bit operating system in a virtual machine mode. These operating systems can either be loaded from the A: drive or from disk images stored on your hard disk.
This article written by Stephen Chapman, Felgall Pty Ltd.