From their homepage:
Penpot is the first Open Source design and prototyping platform meant for cross-domain teams. Non dependent on operating systems, Penpot is web based and works with open web standards (SVG). For all and empowered by the community.
https://hub.docker.com/u/penpotapp
They are using several docker containers (frontend/backend/exporter), and they suggest using docker-compose in their setup guide.
This is a promising open source alternative to Figma/Sketch, for those familiar with the design world. I think this would be a fantastic addition to the linuxserver landscape.