Demoscene is an art form where coders show off their talents (coding, graphics, music, optimisation).
Scene competitions and parties run regularly all around the world and cover a diverse range of hardware platforms from the latest PCs and consoles through 16-bit and 8-bit machines and right down to tiny microcontrollers.
Competitions sometimes impose challenges such as size limits for the demos (64Kb and 4Kb) to test the coders optimisation skills.
One of my favourite set of demos is at it might look dated now but consider if you could do better with an 8MHz CPU, 1MB RAM and an 800KB floppy disk for storage!