Just discovered recently the Statebox project, a visual programming platform based on a refreshing mix of CS ideas ranging from Petri nets to dependent types. It is all articulated around a rigorous category-theoretic foundations, so as to "maximize compositionality". There is also a nice blog post on Azimuth's blog describing the genesis, philosophy, and influences of the project. I think it quite matches the "welcoming, cooperative, and revolutionary spirit" of the FoC community!

See also http://petrinet.org, an interactive explanation of Petri Nets built using Statebox.