Great list of languages that don't fit the conventional families. I've been curious about some of them, like Petri nets and term rewriting, and will enjoy exploring the others.

Found a working link to the paper about propagators.

The Art of the Propagator, Alexey Radul and Gerald Jay Sussman. https://groups.csail.mit.edu/mac/users/gjs/6.945/readings/ar... (PDF)

pure [https://agraef.github.io/pure-lang/] is probably the most "practical" term rewriting language, though mathematica is the most used one by far.

<snark>So they reinvented speadsheets?</snark>