Ideally I would like the following requirements met:
- Free solution.
- Multiple users can log in at once.
- It's shell only (no Remote Desktop!)
I have full admin rights on the box.
As near as I can tell, we did not pay for telnet services, either, so that's not an option, not that I'd know how to set that up either. That'd be an acceptable answer if nothing else presents itself and it's well documented.