Which lightweight database should I use in a Firefox extension?

Question

I currently use a flat-file to store data in a Firefox Extension, but think this is inadequate.

Which lightweight databases are commonly used within Firefox extensions?

Answer 1

SQLite is built in to recent versions of Firefox for use as a data-storage mechanism. More information, and examples of how to use the FF wrapper API, can be found on MDC.

Answer 2

sqlite, used be ff itself