tldraw is an infinite-canvas SDK for React that developers use to build whiteboards, diagrams and other canvas tools. It provides real-time multiplayer collaboration with live cursors and presence, drawing tools, shapes, text, arrows and an Editor API for adding custom shapes and tools. The same technology powers tldraw.com, a collaborative whiteboard that the vendor describes as free and instant. Starter kits, including a multiplayer one, help teams get going quickly.
The source code is on GitHub under the tldraw licence: development use is free, while production use requires a licence key, according to the repository. The multiplayer starter kit is self-hosted and built on Cloudflare Durable Objects, so an organisation can run the collaboration backend on its own account and infrastructure. The tldraw site does not say where boards on tldraw.com are stored. Organisations that need control over data location and jurisdiction are therefore better served by building on the SDK with their own backend than by relying on the hosted service.