Control a computer over the network

There are so many means how you can take control over a Linux computer:

program	mean	browser enablement possible	CLI only access possible
ssh (successor of telnet and rsh)	issue commands to a remote computer	no	yes
shell in a box, ajaxterm	issue commands to a remote computer via a browser, also over the borders of a typical corporate network	yes	no
xdmcp	get a graphical login to a desktop	no	no
vnc	get a graphical desktop on a remote computer, sharable with other users	yes*	no
x11vnc	take over a graphical session that has been started out of vnc	no	no
guacamole	share a Linux desktop over a browser	yes	no
nx	get a low-latency graphical login to a desktop	no	no
webex	take over a graphical session using a browser	yes	no

* you will not be able to cross a typical corporate network. You will need access to more ports on the server than 80 and 443.

Access the display on a remote computer