Cambridge held its STV elections for city council and school committee last night, and since I live nearby, I decided to stop by and watch how they count the votes. Cambridge has been doing STV elections since 1941, and it shows by how organized they are. Here is my understanding of how the vote counting worked.

Cambridge uses ballots where the voters fill in bubbles with a pen to rank the candidates. Here is an example of this year's ballot.

Sequioa Voting Systems makes voting machines, e.g., the physical devices that one uses to enter votes. Historically, these voting machines are called "voting systems," which can be confusing since other people use the term "voting system" to refer to the method of counting votes, e.g., instant runoff voting.

Sequioa has recently announced that it will release an open-source voting system. Here is a quote from the press release:

There are three papers in Voting matters Issue 27, now available at the Voting matters web site:

• The paper by Joseph Durham and Peter Lindener, Moderated Differential Pairwise Tallying, considers a method of electing candidates using a preferential ballot which is quite unlike STV. The paper details the rationale behind the method, using Borda scores and Condorcet as starting points.

  As with all such methods, it is difficult to convince people to use a new system, even given a detailed analysis of its effects. How do voters react to knowing that later preferences can affect the earlier ones?

That's actually the title of a paper that Douglas Woodall published in Voting matters back in 2003. Woodall's introduction says, in part:

Announcing OpenSTV version 1.5 -- Software for computing the single
transferable vote, instant runoff voting, Condorcet, approval, and many
other voting systems. More details and download links are at
http://www.OpenSTV.org.

The most significant changes in this release are the following:

-- Improved format of election results
-- No limit on the number of candidates (previously was limited to 255
candidates)
-- Election methods are now done as plugins so users can add their own
methods (although only for advanced users at this point).
-- Cambridge STV can save the winner's ballots in files for determining
replacements after a vacancy
-- Added statutes of some rules to the documentation
-- Added draft of New Zealand Meek (work in progress)
-- Added new method called QPQ