A Categorical Theory of Patches (2013)

[haskellandchill]

https://arxiv.org/abs/1311.3903

[vlmutolo]

I believe this is the paper that inspired Pijul.

https://pijul.org/

[Koshkin → vlmutolo]

Or Darcs?

http://darcs.net/Using/Model

Edit: Darcs was first released 10 years prior. (So, with Darcs this may be the other way around.)