We have a login server which is shell.ima.umn.edu. Users can connect to shell.ima.umn.edu from outside the IMA thru SSH. There are some SSH clients for Windows/Mac for example PuTTY. PuTTY is freeware, and we do have a version on our server at http://www.ima.umn.edu/putty.exe although it is most likely not the most recent version.