OpenSSH (which Linux, BSD and many other systems use) has sftp installed as an ssh subsystem. Have a look at the last few lines of your /etc/ssh/sshd_config file.
Probably looks something like this:
Code:
Subsystem sftp /usr/lib/ssh/sftp-server
That's it. As for configuring how this will be accessed you will want to learn more about ssh. I recommend looking at
There is not a GUI to configure this that I know of, unless you're talking about a graphical text editor or something.
