OTSoft:  Optimality Theory Software

Bruce Hayes


Version 2.5 (current)

Last update to this page:  April 11, 2021

Download version 2.5
Download beta version 2.6

OTSoft is a Windows program meant to facilitate analysis in Optimality Theory* and related frameworks by using algorithms to do tasks that are too large or complex to be done reliably by hand.  The following functions are supported:

OTSoft was programmed primarily by Bruce Hayes, with contributions by Bruce Tesar and Kie Zuraw.


What's new with version 2.5

What's new with version 2.6 beta

How to Download and Run OTSoft

On a Windows computer, use your browser to download OTSoft2.5.zip.  Put it in some folder where you can find it.  

To unpack:  

Most computers come with an unzipping program.  Find one on the web if yours does not (Google "free unzip program").  Next, go to the folder where you put your file.   Once you're there, use your unzipping software. 

Unzipping will produce the folder OTSoft2.5.  Click on this folder to look inside it.   It will looks something like this:

view of folder

Or perhaps like this, if your computer is set up to suppress file suffixes:

folder without suffixes


To run it:

Either way, use your mouse to click on SampleInputFile(.txt) and drag it onto the program OTSoft2.5(.exe). The program will start up, and the interface should give you various options for ranking/weighting the constraints, calculating the ranking arguments, doing the factorial typology.

The program is pretty self-explanatory (every button has words on it, and there are drop-down menus at the top).  But you might benefit from reading the manual.

For best performance, link up OTSoft to other Windows programs, of which five are possible:  your word processor, your spreadsheet program, your web browser, your graphics editor, and the magnificent "dot.exe" from the people at GraphViz. To do this, go into the program folder and edit the self-explanatory file OTSoftAuxiliarySoftwareLocations.txt.

Papers describing the algorithms



If you make public an analysis that you worked out and/or checked with OTSoft, you may cite the software as follows:


Source Code

OTSoft is written in a programming language (Visual Basic 6) abolished long ago by Microsoft (it was too easy to learn and use, so they got rid of it!). You would have to find a copy of this old language to modify the program.  But Basic is extremely transparent, almost like prose, and you could easily read the algorithms off of it.  Source for 2.5.


Archive of earlier versions



Optimality Theory (OT) is a wide-employed theoretical framework used in contemporary linguistics.  The original reference for OT is Prince and Smolensky (1993); good textbooks have been written by René Kager and John McCarthy.


Last modified April 7, 2021

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