The "modular" API weighs in at 35 KB and is framework agnostic, meaning that you can integrate it with existing frameworks such as jQuery and Dojo Toolkit without conflict. Designed and created by Geoff Hendrey and Brent Hamby, two developers from the Bay Area, NextDB.net is currently in public alpha and available for developers to test out.
The NextDB.net team has put together a screencast tutorial of the API, as well as documentation, a getting started guide, and a security FAQ page. Demos of the API in use are also available, including this demo of a Google Maps mashup that used the API.
This is an innovative and creative approach to enabling data-driven functionality for mashups (and web sites in general), and it seems that there is great potential for this type of database to be used in mashups that need database functionality, but which do not require a locally-available database.