For questions about x11vnc, a VNC server for real X displays.
x11vnc: a VNC server for real X displays
x11vnc allows one to view remotely and interact with real X displays (i.e. a display corresponding to a physical monitor, keyboard, and mouse) with any VNC viewer.
It has built-in SSL/TLS encryption and 2048 bit RSA authentication, including VeNCrypt support; UNIX account and password login support; server-side scaling; single port HTTPS/HTTP+VNC; Zeroconf service advertising; and TightVNC and UltraVNC file-transfer. It has also been extended to work with non-X devices: natively on OS X Aqua/Quartz, webcams and TV tuner capture device.
(source: karlrunge.com)