PyPN (pronounced like the famous hobbit) is a python library and linear logic theorem prover based on proof nets.
Currently, it supports multiplicative linear logic (MLL) plus the n-ary MIX rule, but it's designed to be fairly hackable for those who want to implement their favourite flavour.
The prover itself works best run inside of a Jupyter notebook. In that case, successful proofs are displayed visually as proof nets with draggable nodes.
To see the basic features of the library/prover, check out notebooks/Basics.ipynb.
PyPN arose as a weekend hack session based on some of the graph drawing features from PyZX, a quantum circuit optimiser library. In recognition of that, here's a plane that says PYPN: