gitmodel

https://github.com/pauldowman/gitmodel

GitModel persists Ruby objects using Git as a data storage engine. It's an ActiveModel implementation so it works stand-alone or in Rails 3 as a drop-in replacement for ActiveRecord or DataMapper. Because the database is a Git repository it can be synced across multiple machines, manipulated with standard Git client tools, can be branched and merged, and of course keeps the history of all changes.