Academics working on voting theory have several of these as well: https://voting.ml/ https://voting.ml/ https://opra.cs.rpi.edu/ https://opra.cs.rpi.edu/ https:

Academics working on voting theory have several of these as well: https://voting.ml/ https://voting.ml/ https://opra.cs.rpi.edu/ https://opra.cs.rpi.edu/ https://pnyx.dss.in.tum.de/ https://pnyx.dss.in.tum.de/ http://www.robovote.org/ http://www.robovote.org/ https://whale.imag.fr/ https://whale.imag.fr/