1. virtual framebuffer X server for X Version 11 From whatis

2. virtual framebuffer X server xvfb provides an X server that can run on machines with no display hardware and no physical input devices. It emulates a dumb framebuffer using virtual memory. The primary use of this server was intended to be server testing, but other novel uses for it have been found, including testing clients against unusual depths and screen configurations, doing batch processing with Xvfb as a background rendering engine, load testing, as an aid to porting the X server to a new platform, and providing an unobtrusive way to run applications that don't really need an X server but insist on having one anyway. This package also contains a convenience script called xvfb-run which simplifies the automated execution of X clients in a virtual server environment. This convenience script requires the use of the xauth program from xbase-clients, hence the suggestion of xbase-clients. From Debian 3.0r0 APT