Latest open source version of OpenSTV voting software, which was GPL'd until going proprietary in mid-2011 (apparently after 1.7).
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OpenSTV: Introduction & Historical Notes

This is OpenSTV 1.7. OpenSTV is open source voting software that implements the single transferable vote (STV) election method.

The canonical location for this archived version of OpenSTV is Please note that this version is not being maintained, however. (We heard that a fork of OpenSTV is being maintained over here, but we don't know much about it nor which version it's forked from.)

If you're looking for voting software, as of May 2016 the places to start are probably:

Apache STeVe was used in a test Board election at the Apache Software Foundation. The user interface is pretty good, and it supports the "Single Transferable Vote" method as well as some others. (Oddly, it seems not to have direct support for Approval Voting, but that ought to be very easy to add if someone wants it, since implementation-wise it's really a subset of the STV algorithm anyway.)

As for voting method: Choosing a voting system is complex, and there is often not an obvious right choice. It depends on what kinds of outcomes your electorate should optimize for, and of course, if you knew the answer to that, you probably wouldn't be needing to hold a vote in the first place. However, for most purposes, Score Voting, Approval Voting, or STV are fine, and any of them is a big improvement on the generally terrible "one vote per voter no matter how many candidates" method that seems to currently be the default for most elections that matter. If you want to dig deeper, this tweet leads to conversation and links about the pros and cons of various voting methods.

OpenSTV History

OpenSTV was released under the GNU General Public License version 2 (or later) until around mid-2011. At that point its main author, Jeff O'Neill, took future versions proprietary. As of this writing, the latest version along the proprietary line is 2.1.0 and it is available for purchase from It looks like O'Neill also offers an online web app at, in case you don't want to set up OpenSTV 2.x yourself.

The last open source version of OpenSTV he released was 1.7, which is available here. If this were ever to become the root of a new open source development line, good manners would dictate that we change the name to something other than "OpenSTV" (unless O'Neill prefers it stay the same). However, that's not an issue at this point, as what's here is exactly what was released as "OpenSTV 1.7" back in 2011.

For more information about OpenSTV's history, the temporary disappearance of the 1.7 source code from the public Internet, and its eventual restoration, see:

Some other open source voting software systems are:

Below is the original README.txt from Jeff O'Neill (just reformatted to Markdown for consistency with the rest of this file):

Original README.txt from OpenSTV 1.7

Revision $Id: README.txt 578 2009-08-26 01:13:50Z jeff.oneill $


OpenSTV is a program for implementing the single transferable vote (STV). STV is used for electing a group of people (e.g. council, committee, legislature) and it provides for proportional representation of the electorate. The idea behind proportional representation is that the demographics of the elected group should, at least roughly, match the demographics of the electorate. The beauty of STV is that there are no reserved seats and the proportional representation arises naturally. For more information see

In an STV election, each voter simply ranks the candidates in order of preference. The rules for counting the votes with STV are more complicated than winner-take-all elections. The votes can be counted by hand, but it is useful to have a computer program to speed up the process. There are several variations of STV, but most users should use the default options.


See for more information.

Jeff O'Neill jeff.oneill at