Mac® Security Bible

7.3. Screen Sharing

Screen sharing is a generic term used for any system that lets you see and control another computer remotely — putting an image of its screen on your display and using your own keyboard and mouse to control it just as though you were sitting in front of it. This capability is essential for system administrators and anyone else called upon to do remote troubleshooting; it's also useful for people with more than one computer in different locations, such as one at home and another at work. If you want to run programs on a remote computer, see what's on its screen, or do more extensive operations than you can accomplish with file sharing or remote login via SSH, screen sharing is just what you need.

For many years, it's been possible to do this using third-party software, such as Timbuktu or the open-source VNC. Using such software, you can even control a Mac from a Windows PC or vice versa. Leopard and Snow Leopard include a version of VNC that offers comparable capabilities, and thanks to Apple's Bonjour networking and Back to My Mac, you can often share another Mac's screen without knowing its IP address or domain name.

Of all the ways in which you can share resources on your Mac, screen sharing is the most powerful — it gives the person on the other end potentially unlimited control. Of course, if you're sitting in front of a Mac that someone else is controlling, you can turn off screen sharing, disconnect the network cable, or turn off the computer. But if ...