CommandMon was written to allow you to monitor the output of UNIX commands such as ls, ps, vm_stat, etc. Although any UNIX command will work, some may not give you the desired results (vi for example).
Do NOT launch interactive programs (NeXTSTEP apps, gdb, etc.) with CommandMon. It does a pretty good job of hanging CommandMon.
Let me know if you like/dislike this program, as well as any new features you'd like to see it have...You can get in touch with me through my email address in the info panel.
