Just watch, listen and enjoy :). The demoscene is an international computer art subculture that specializes in producing demos: small, self-contained computer programs that produce audio-visual presentations. The main goal of a demo is to show off programming, artistic, and musical skills. The demoscene's roots are in the home computer revolution of the late 1970s, and I first was introduced to it on my old Commodor Amiga :)
credit to griffpatch