Multiple Monitor Computing: A Significant Productivity Trend in its Very Early Stage of Adoption

Multi-monitor, also called Multi-display, Multi-head, and Dual-Monitor, is the use of multiple physical display devices, such as monitors, televisions, and projectors, in order to increase the area available for computer programs running on a single computer system. Microsoft describes this setup as "one of the best ways to improve your productivity". Randy Pausch recommended multiple monitors for improving personal productivity in his Time Management lecture. Contemporary versions of Microsoft Windows, Mac OS, and X Window System (used by GNU/Linux) all support multiple monitors. Dual monitor support once depended on specialized proprietary video drivers supplied with few video cards, along with a multi-display-supporting GUI system. Support for multiple monitor configurations was added as a standard feature in Microsoft Windows in Windows 98. It has been a standard feature in all versions of Apple's Mac OS X (introduced in March 2001), and was a standard feature of the first color Macintosh II introduced in 1987. By adding up to two additional video cards, the Mac supported up to three monitors, although operating system support for multiple monitors wasn't introduced in Windows until the mid 1990s. The all-in-one Mac SE/30 featured a small black & white screen, but could drive an external color monitor.
Link: http://en.wikipedia.org/wiki/Multi-monitor