I know there have been suggestions and comments on Figma to Webstudio. Keeping with opensource, I would like to suggest penpot as a contender down the road. https://penpot.app/
hey, just circling back to this, Penpot is getting more robust nowadays. I'm thinking along the workflow - create our design system, components, and have it sync to our "components library" in Webstudio. That would be awesome π