4Klang is a music synthesiser tool by Alcatraz optimised for use in 4K intros.

Crinkler is a compressing linker, created by Mentor and Blueberry, popularly used on 4K intros to keep the executable files as compact as possible.

Rocket is a a sync-tracker – a tool for synchronizing music and visuals in demoscene productions. It is open source, and can be retrieved from GitHub.