OpenTally is an application for counting various preferential voting elections, with an academic focus, and emphasis on configurability.
OpenTally may be used in a number of different ways:
- as an online web application, no installation or special software required
- as a standalone command line application
- as a Rust library within another application
OpenTally accepts data in the BLT file format, and can count votes using:
- weighted inclusive Gregory STV (e.g. Scottish STV)
- unweighted inclusive Gregory STV (e.g. Australian Senate STV)
- exclusive Gregory STV (e.g. PRSA 1977 and ERS97)
- Meek STV – with tree-packed ballots for efficient computation
- Wright STV
OpenTally is highly customisable, including options for:
- different quotas and quota rules (e.g. exact Droop, Hare)
- calculations using fixed-point arithmetic, guarded fixed-point (quasi-exact) or exact rational numbers
- different tie breaking rules (backwards, random, manual) with auditable deterministic random number generation
- multiple constraints (e.g. affirmative action rules)
- equal rankings
See the quick start guide for how to use OpenTally online.
OpenTally may also be invoked as a command line application. Run
./opentally --help to view help.
For example, run
./opentally stv path/to/blt_file.blt --ties backwards random --random-seed foobar.