The focus here is to find a potential "universal API" for a data storage abstraction at its lowest level. It will adapt itself to a particular JS environment and provide a portable synchronization mechanism that can target various backends, beginning with CouchDB. No associations between data are stored because this is intended to be a "lowest common denominator" of key-value stores; it will hopefully lend itself well to a variety of query models.
Did you note, though, that I did not use the word "browser"? JS runs in a variety of environments, but persistent storage is a tough nut to crack. This project is closely related to my other main projects, Quanah and Web Chassis :-)
Try it here.