KDrive

Around 2000, XFree86 was a multi-megabyte server with loadable modules and a configuration file that needed hand-holding. Keith Packard wanted the opposite for Linux on Compaq's iPAQ and similar handhelds: a statically linked server with no configuration that drew straight into the kernel's framebuffer. The result, first called TinyX and then KDrive after its author's first name, fit in about a megabyte. It came in one flavour per substrate: Xfbdev for the framebuffer, Xvesa, which talked directly to the graphics card's BIOS and needed no drivers at all, and a handful of tiny servers for individual chips.

Its acceleration layer, KAA, became the model for EXA, which X.Org brought into the full server in 2005. In 2004 Matthew Allum built Xephyr on KDrive: a server that renders into its own buffer and shows the result in a window on another X server. When X.Org cleaned house around 2010 the hardware servers were removed, the kernel's mode setting having made them redundant, but Xephyr stayed and is today the only thing still calling itself KDrive.