Unfortunately RDP server on Linux is a bit tricky to set up, and involved some amount of compiling for me. On the other hand, I think `x11vnc` is pretty easy to get started with. I followed this guide, and it worked for me no problem: http://askubuntu.com/questions/229989/how-to-setup-x11vnc-to...

My guacamole server then connects to x11vnc so I still get RDP-like performance across the internet.

Edit: you'll also want to make an Upstart job for x11vnc so that it starts on boot, and restarts if (when) it dies. You can just copy any of the basic upstart jobs in /etc/init.d/*.conf and investigate. You also may want to make x11vnc start after your X server: http://upstart.ubuntu.com/cookbook/#run-a-job-before-another...

There is a lot of fiddly business :/