This is an extension of OpenPonk tool that adds Petri net diagrams.
It allows crating places with tokens, transitions and arcs. Created Petri nets could be simulated in a random or user-picked order. Petri nets metamodel is included in the repository.
Requires Pharo 7 or 8 image - clean or with loaded OpenPonk.
In Playground, execute following script:
Metacello new
baseline: 'PetriNets';
repository: 'github://OpenPonk/petrinets/repository';
load