Demoscene
A subculture competing to wring impossible graphics and music out of limited hardware — with programs that serve no purpose whatsoever.
The origin is 1980s software piracy: groups that cracked copy protection added a small signature before the game, a cracktro with scrolling text and music. The signatures became competitive in their own right, detached themselves from the pirated copies and turned into demos — non-interactive audiovisual works shown at demoparties such as Assembly in Finland and Revision in Germany.
The constraint is the point. An entry in the 4K category must fit in 4096 bytes, music and all graphics included, which forces procedural generation and hand-optimised assembly. The scene is strongest in the Nordics and Germany, and heritage status has followed: Finland added the demoscene to its list of intangible cultural heritage in 2020, Germany did the same in 2021.