PuTTY is a free SSH client.

Mosh is a tool used to connect from a client computer to a server over the Internet, to run a remote terminal. Mosh is similar to SSH, with additional feature…

PAC is a SecureCRT/Putty/etc (connections manager with automations) equivalent for the Linux world.

KRDC is a client application that allows you to view or even control the desktop session on another machine that is running a compatible server.