STEMMA Project

These pages describe a generalised data model and source format for genealogy, family history, and micro-history (STEMMA
®). This might be used for multiple different purposes, such as:


  • Definitive source format for data
  • Import/export or exchange format (including over the Internet)
  • Database load-format
  • Backup format
  • Historical “document” format


This R&D project came about because I didn’t want my family history data locked in to any single commercial product. Plus I didn’t believe that existing data models were able to represent my data completely and accurately because of its micro-history approach. STEMMA incorporates biological lineage (as in family trees), structured events, and rich-text narrative to go beyond family history to address the micro-history of arbitrary people, places, or events.


As a software architect I have the luxury of being able to provide something myself. I therefore decided to define and implement a new model and format that did precisely what I required of it rather than compromising. Converting to other data models should be straightforward if STEMMA is general enough, albeit at some potential loss depending on the target model.


The STEMMA data model may be a source of inspiration to other people or groups with the same goals, primarily because it was developed independently and with minimal influence from other models and products.


This documentation constitutes V2.1 of STEMMA, and supersedes previous specifications (V2.2 release imminent).



This site is located via

Content created: 2 January 2012. Last updated 3 December 2013.

Tony Proctor is currently a software architect working from rural Ireland.


Copyright © 2014 Tony Proctor. All Rights Reserved

® STEMMA is a registered trademark of Tony Proctor.