These pages describe a generalised source format for history data (STEMMA) that might be used for multiple different purposes. For instance:

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

This 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.

Having been a software architect for many years, I have the luxury of being able to provide something myself. I therefore decided to define and implement a format that does precisely what I would expect of a universal source format. Converting to other data formats should straightforward if STEMMA is general enough, albeit at some potential loss depending on the target format.

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 formats and products.

This documentation constitutes the first fully working version of STEMMA, and supersedes previous drafts specifications.