Yeah sorry about that. I removed Vertebrae and Sentry because they were over-engineered and weren't that useful. Vertebrae did some things to help with relations and identity maps in Backbone but there are already better solutions out there now.
e.g.
https://github.com/PaulUithol/Backbone-relational
https://supportbee.com/devblog/2011/11/25/identity-map-for- backbone-js-models/
https://news.ycombinator.com/item?id=3276990 (Discussion on jashkenas pattern for a solution to identity maps)