tldraw

tldraw is two things at once: a drawing application at tldraw.com and an SDK that other products use to add a canvas. The SDK is the more consequential half - it is a set of React components and a document model for building an infinite canvas into an application. The document model is the part that distinguishes it from a plain canvas library. Shapes are records with types and properties, the store is a reactive document, and collaboration is expressed as changes to that document. That structure is what lets an application persist a drawing, sync it between clients, and extend it with custom shape types. The editor is published as a package, and the hosted application at tldraw.com is a demonstration of what the SDK can build. For a product that needs a whiteboard, a design surface, or an annotation layer, the SDK is the reason to look at it.