About PMx & PMxLite



PMx is a package of demographic and genetic analysis tools to assist with the management of breeding programs for wildlife species. PMx was developed by Jonathan Ballou (Smithsonian Institution/National Zoological Park), Robert Lacy (Chicago Zoological Society), and JP Pollak (Cornell University). The concepts and design of PMx benefitted immensely from input by the AZA Small Population Management Advisory Group, the EAZA European Population Management Advisory Group, Species360 (formerly the International Species Information System), and colleagues in zoos and conservation organizations around the world.

PMxLite: PMx Made Simpler

PMx is a software package that supports the demographic and genetic management of pedigreed populations. However, most beginner and casual users do not need many of its advanced features and options. These are hidden in PMxLite, creating a less intimidating user interface and easier application of its core demographic and genetic tools for analyzing a population’s status and making basic management recommendations.

PMx is licensed under a Creative Commons Attribution-NoDerivatives 4.0 International License.

  • How to Cite

    Ballou, J.D., Lacy, R.C., Pollak, J.P., Callicrate, T., and Ivy, J. (2023). PMx: Software for demographic and genetic analysis and management of pedigreed populations (Version Chicago Zoological Society, Brookfield, Illinois, USA. Available from http://www.scti.tools

    Please acknowledge SCTI in your reports and publications. Suggested wording:

    PMx software (Ballou et. al. 2023) is provided under a CreativeCommons Attribution-NoDerivatives International License, courtesy of the Species Conservation Toolkit Initiative (https://scti.tools).

  • Key References

    Lacy, R.C., J.D. Ballou, & J.P. Pollak. 2012. PMx: Software package for demographic and genetic analysis and management of pedigreed populations. Methods in Ecology & Evolution 3:433-437.

    Lacy, R.C. 2012. Extending pedigree­ analysis for uncertain parentage and diverse breeding systems. Journal of Heredity 103:197-205.

Which version of PMx is right for me?

PMxLITE: Use this version if you are a beginner with PMx or use PMx only occasionally for standard genetic and demographic management.

PMx: Use this version if you are an advanced user of PMx and have a need for more complex demographic and genetic analysis.


PMx is constantly changing. We fix bugs when they are identified, and when we have time to fix them. We also add new or improve on old analyses and features when we believe that they will enhance the management of populations, and we have the time to add the enhancements. We frequently make small changes to screen lay-outs, screen text, and file formats when we feel that the change will improve the program for users (and we have time). The PMx program will alert users on the opening screen if a newer version is available for downloading.

Note that we do not guarantee that all changes to the program have been documented here. In particular, we won’t list here many very minor changes made to the interface.

We also do not guarantee that all bugs in code or errors in algorithms have now been fixed. Reports of apparent bugs can be made at scti.tools/help-support/ .

  • 18 December 2023 (version 1.8.0)

    PMxceptional, an extended version of PMx for analysis of populations with stage-based (rather than age-based) demography, was added to the PMx installation package. In addition, various minor bug fixes were made to the PMx code.

  • 25 March 2022 (version 1.6.5) A change was made to where PMx stores the list of Recent Projects. This will avoid a problem that was occurring on some PCs that would cause PMx to fail to be able to save projects after a new version was installed. A minor disadvantage of this change is that after you update to a new version, your Recent Projects list will reset to start accumulating projects again. A change was also made to where PMx stores a temporary file. This should prevent a problem that was occurring on some computers whereby PMx would crash with an error message saying that access to a file was blocked when the user attempted to save a project.

  • 2 August 2020

    No change was made in the program code, but a default option in the PMxSettings files that are installed with the program was changed. This was necessary because we found that the default option caused problems on computers that use non-US data formats.

  • 18 May 2020

    PMxLite is now installed along with PMx, as two separate programs. They will both use the PMxProjects folder (by default), and any PMx project can be opened in either PMxLite or the full PMx. The two programs keep their own Recent files list and can be independently customized.

  • 6 January 2020 (version 1.6.2)

    A few minor changes have consolidated into a new release.

  • 10 August 2019 (version 1.6.1)

    PMxLite and the ability to customize which features are presented and accessible in the user interface were added. See the documentation in CustomizingPMx.docx (installed in the Manuals&Guides subfolder of PMxProjects.)

    When detailed demographic information is selected in the Demography Settings, then the life tables will show also SEs and confidence intervals for Lx values.

  • 28 June 2019 (version 1.6.0)

    An error was fixed in the calculation of an individual’s kinship to self in the case of MULT parents and empirical kinships specified.