Everything associated with the CCA can be done using only commandline access to the remote system. The primary tool for this kind of access at present is the Secure Shell protocol, (SSH). Both free and commercial implementations of ssh are widely available. Among the most common are OpenSSH for Linux(-like) systems and PuTTY for Windows. When we describe specifically how to do something with an SSH client, we will describe it for these two packages. However we won't be using any unusual capabilities of SSH, so most other implementions probably have an equivalent.