Excalidraw whiteboard – easily sketch diagrams with a hand-drawn feel
Excalidraw is pretty cool, but its main drawback is that is has no backend. The drawings cannot be persisted to the server, and you cannot collaborate with someone on a drawing unless you are both connected at the same time.I maintain another opensource whiteboard web application that has a slightly different set of features, but allows persisting drawings to the server. It's called WBO :- https://wbo.ophir.dev/