Penpot

Penpot is a free, open-source design and prototyping tool built for cross-domain teams. It runs in the browser and is based on open web standards (SVG), making your designs portable and not locked into a proprietary format.

Penpot offers vector editing, components and libraries, interactive prototyping with transitions and animations, design inspection for developers (like Figma's dev mode), grid and flex layout support, multi-user collaboration with comments, and export to various formats. It is fully browser-based and can be self-hosted with Docker.

For organizations that need a collaborative design tool but are concerned about data privacy, vendor lock-in, or the rising cost of Figma licenses, Penpot provides a compelling open alternative. The Penpot team is actively developing it with frequent releases, and it supports plugins for extensibility.