How do I set up a cloud server that can be SSH'd to?

[Bobhaxor]

Harvard has a cloud server for their CS50 class. You can access it through the command prompt/terminal via SSH. It holds a variety of programs, like nano, vi, and the ability to generally take commands and run programs. It allows people to some how program directly in their command prompt, but as though they are running nano, then easily just run their programs.

How did they set such a thing up? How might I set up a server that can be SSH'd into. Where people can browse through and edit files using nano or vim all through their cmd or SSH client?

[xtropx]

Any linux box can be setup to ssh into and contain various config files one could modify. Grab a copy of any linux distro and install it in a virtual machine or on a spare PC. Then install sshd. I recommend Ubuntu if you are not familiar with linux.