Within the computer subculture known as the demoscene, a
non-interactive multimedia presentation is called a demo. Demogroups create
demos to demonstrate their abilities in programming, music, drawing, and 3D
modeling. The key difference between a classical animation and a demo is that
the display of a demo is computed in real time, making computing power
considerations the biggest challenge. Demos are mostly composed of 3D
animations mixed with 2D effects and full screen effects.
The boot block demos of the 1980s, demos that were created to
fit within the small first block of the floppy disk that was to be loaded into
RAM, were typically created so that software crackers could boast of their
accomplishment prior to the loading of the game. What began as a type of
electronic graffiti on cracked software became an art form unto itself. The
demoscene both produced and inspired many techniques used by video games and 3D
rendering applications today - for instance, light bloom, among others.