A fundamental feature of our application is allowing users to create complex and sometimes large diagrams dynamically using JavaScript. We used React along with JointJS and JointJS+ and our integration process with React was quite seamless. We were able to interweave JointJS with our React components and their associated behavior using JointJS events.  What helped enormously were the example demos and applications built by the JointJS team that we could use as a reference. When we hit a problem, we could either find a solution just by googling or asking the JointJS team. They were highly responsive even before we bought the support package. Overall we found JointJS to be a solid library full of features.