This dialog box is part of the Language editing modes dialog. These options allow you to specify the names of external utilities (commands or programs) which should be used under various circumstances.
"I have a confession to make. I'm a vi user. I've tried other programmers editors
but my fingers just could not make the switch. All the text editors I tried
forced me to learn all new commands...Then I found CRiSP. I was saved, it has a
wonderful vi emulation mode.