Blit isn't content with just being a graphical user interface
with multiple windows and right-click context menus. The windows
can also overlap, and the system employs, true to its UNIX base,
full multitasking. The video below demonstrates how you could
edit code in a text editor, switch to a different windowed
terminal and execute make, and play Asteroid in another
overlapping window while the code compiled. Further along the
video, it shows an application for integrated circuit design
with a debugger running in a separate window. It ran on a
Motorola MC68000 processor in 1982, but would be ported to the
Western Electric WE32000 microprocessor so it could be used on
commercially available machines like the AT&T 5620 starting in
1984. It was created by Rob Pike and Bart Locanthi, and detailed
in this paper on the subject. For instance, this is how windows
(or layers, as they call them) were implemented: Interestingly
enough, the goal behind creating Blit was to make graphical user
interfaces run on less power