The demoscene is a computer art subculture that specializes in producing demos, which are non-interactive audio-visual presentations that run in real-time on a computer. The main goal of a demo is to show off programming, artistic, and musical skills. The demoscene first appeared during the 8-bit era on computers such as the Commodore 64, ZX Spectrum and Amstrad CPC, and came to prominence during the rise of the 16/32-bit home computers (the Amiga and the Atari ST). In the early years, demos had a strong connection with software cracking. When a cracked program was started, the cracker or his team would take credit with a graphical introduction called a "crack intro" (shortened cracktro). Later, the making of intros and standalone demos evolved into a new subculture independent of the software (piracy) scene.