OS/2 on Virtualbox guide
There is this interesting article about running different versions of OS/2 on VirtualBox. It offers tips for each different version, disk image conversion information and prebuilt images.
When I started looking into getting it working on a virtual machine, I had a hard time finding some crucial information and files, there were steps in the install process that were not explained in the few guides I could find, it wasn't clear to me which versions could be installed, and some of the install files were in formats I couldn't read.
Now that I've figured out all those problems I've created a guide with specific instructions on how to get all major versions working on VirtualBox, complete with sound, video and network in some cases, and you'll find those guides below. I also created prebuilt virtual machines you can just download and press play on.
You owe it to yourself to play with OS/2. It's an amazingly fascinating operating system with some great ideas and features.