FBUI

Framebuffer UI (FBUI) is an in-kernel windowing system for Linux (kernel version 2.6.9 only, currently outdated) that sits on top of the framebuffer subsystem. Unlike the X Window System, FBUI consumes very little memory: the entire subsystem is about 50 kilobytes. FBUI supports features expected of modern windowing systems, such as moveable overlapping windows, multiple windows per application, events and common drawing functions, as well as windows on every virtual console. Graphics operations are executed on a first-come, first-served basis inside the kernel, and there is no server that queues requests.

Included with FBUI is libfbui, which provides abstractions for windows, events, images, fonts, etc., as well as quite a few sample programs such as load monitor, clock, calculator, scribble pad, image viewer, window managers, and a simple MPEG2 player.

FBUI, being only 50 kilobytes, offers solid proof that a windowing system need not be several megabytes in size, as is the case with X Window System.

FBUI is primarily intended to be a 2D graphics system, although it does include a triangle-fill routine.

PLEASE, DON'T MAKE IOCTL POSTS.

But the idea to have a graphical interface in kernel is nice.  You can have kernel consoles, teletype COM ports, modems, why not have graphics too?  With some thinking it can be made a character device.

>>8
But it didn't get much better since the times of Unix Haters Handbook.

>>22
You are right, Firefox and Openoffice on Windows are noticeably faster.  X also lacks consistent keyboard input configuration.  But it doesn't mean that kernel graphics will be better.