Open source FigJam alternative

There are roughly 8-12 viable open source or freemium alternatives to FigJam currently in active development (Excalidraw, Tldraw, Penpot, Miro open-source forks, etc.), but the market is still fragmented and none have achieved mainstream adoption outside niche communities. The core pain point is that FigJam's dominance comes from lock-in, not superior UX—teams stick because it's bundled with Figma, not because it solves collaboration better. What's actually missing is an open source tool that combines real-time multiplayer smoothness, mobile-first design, and dead-simple self-hosting, all without sacrificing the polish that makes FigJam feel native. Most existing alternatives sacrifice either polish (clunky UI), ecosystem depth (limited integrations), or ease of deployment (Docker nightmare). The real opportunity isn't building a FigJam clone; it's building the collaborative whiteboard that works as naturally on iPad as on desktop, syncs without lag, and can run on your own infrastructure. A new entrant should focus obsessively on one use case—design teams, engineering brainstorms, or education—and own that before expanding. The market is expanding because companies increasingly want to escape vendor lock-in and teams want tools that don't phone home to a company's servers.