I gave up on interactive applications like this using web tech- Qt has the QGraphicsView framework which is far and away the best implementation I've seen so fa

I gave up on interactive applications like this using web tech- Qt has the QGraphicsView framework which is far and away the best implementation I've seen so far in terms of programmability. There is a (significant) learning curve, but basically you're just learning how modern windowing systems work (and once you do, the browser model starts to seem awfully clumsy). One of the crazy bits about QGraphicsView is that it provides not only simple primitives and the ability to make arbitrarily nested primitives, you can also render SVG, *and any Qt widget including a web browser) into the space.