Developed by the ODI as a proof of concept, it has now been replaced by Data Curator (GitHub).
I think it would be a good idea to formally archive this repository as it would give a clearer signal to newcomers that it has officially been replaced (not everyone will notice that the last commit was in 2018).
If you leave any tombstone, please point to https://github.com/qcif/data-curator, the new repository for Data Curator, or its entries in the Microsoft and Apple Mac App Stores.
Given this from the README:
I think it would be a good idea to formally archive this repository as it would give a clearer signal to newcomers that it has officially been replaced (not everyone will notice that the last commit was in 2018).