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.
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.