Instant-runoff voting (IRV) is a voting method used in single-seat elections with more than two candidates.

A PHP library based on STV.pm by Jonathan Lundell.

I'm publishing source code for my 2 legacy NewGRFs (ERV and IRV) for OpenTTD which I created using grfcodec back in 2007.

Vote tallying tool that ranks the winners by Instant-Runoff (IRV) rules. Intended for use with Louisiana Youth & Government conference elections.

Analysis of multi-pass IRV elections, a problematic multi-winner form of RCV

JS implementation of Single Transferrable Vote (STV) counting

A visual simulation of four different electoral systems

NSW Legislative Assembly Election Data in PrefLib format.

A library of rank voting algorithms

A toolkit for alternative voting methods. Initially to support Rankled and Range Ballots for IRV, Boorda, and Pairwise/Condorcet. Future support planned Multi-member methods.

This plugin allows sorting a list of options by preference of the user, instead of just selecting one.

Simulating different electoral systems

The reference implementation of the single transferable vote (STV) system used for student government elections at Carnegie Mellon University.

Open Source voting platform, by the Center for Election Science

Droop STV Election Counter

Voting systems comparison website. Simulate a single election in dozens of different voting methods including plurality, borda count, instant runoff, bucklin, copeland, and many more!

A rust library for tallying votes