A program running within a command line window. Unlike under Windows, these don't just immediately close upon completing execution, which is a very nice touch.

Attempting to close a command window with unsaved work in it brings up this dialog box.

Attempting to open an already open program brings up this dialog box.

The Print Manager isn't much to look at when you aren't printing anything, but here it is nonetheless.

This is the OS/2 "System Editor", a program roughly equivalent to Notepad on Windows. It can, however, open up large files without issue.