CloudPlug, a plug computer developed by CTERA Networks
Seagate Dockstar, a plug computer similar to the SheevaPlug
A plug computer is an external device, often configured for use in the home or office as a compact computer. It consists of a high-performance, low-power system-on-a-chip processor with several I/O ports (USB ports, ...) and typically runs any of a number of [Linux] distributions. Most versions do not have provisions for connecting a display and are best suited as for running media server, back-up services, file sharing and remote access functions, thus acting as a bridge between in-home protocols such as Digital Living Network Alliance (DLNA) and Server Message Block (SMB) and cloud based services. There are, however, plug computer offerings that have analog VGA monitor and/or HDMI connectors, which, along with multiple USB ports, permit the use of a display, keyboard, and mouse, thus making them full-fledged, low-power alternatives to desktop and notebook computers.
The name "plug computer" is derived from the small configuration of such devices: plug computers are often enclosed in an AC power plug or AC adapter.
Plug computers typically consume little power and are inexpensive. One manufacturer claims its $119 plug computer draws 1.2 watts and can cost $2 a year to run.