This repository was used to develop the Simple Definition Format (SDF) for One Data Model definitions. With the publication of SDF version 1.0, that development has now moved to:
https://github.com/one-data-model/sdf
The /language repository is an archive of what happened before that.
We do not want to "archive" it in the github sense because there are still a number of issues with useful ideas in this repository that are worth processing for extensions in future versions of SDF, "archiving" would make these read-only.