DovetailDB is a schemaless, JSON-based database. It is similar in spirit to Amazon's SimpleDB, but allows for javascript to be executed on the server, and, within that context, provides full transaction support.
XBSDB is the tool to operate with data in JavaScript code like with SQL-data. XBSDB stores, arranges and selects data in your scripts. You can insert, delete, update and select records, you can use indexes. JSON-based methods allow data exchange.