Desktop sharing is a common name for technologies and products that allow remote access and remote collaboration on a person's computer desktop through a graphical terminal emulator. The most common two scenarios for desktop sharing are: * Remote login * Real-time collaboration The shortcoming of the above solutions are their inability to work outside of a single NAT environment. A number of commercial products overcome this restriction by tunneling the traffic through rendezvous servers. Apple machines require Apple Remote Desktop (ARD).