Even if the standard said SQL92, the only practical, shippable embedded SQL database today is SQLite. I don't think browser vendors are itching to implement th

Even if the standard said SQL92, the only practical, shippable embedded SQL database today is SQLite. I don't think browser vendors are itching to implement their own SQL databases (or if they did, that they would be any more interoperable than the various relational databases today). So realistically, if we go the SQL route, what will get is SQLite. SQL is a great language and SQLite is a great implementation. But Mozilla knows what happens in the long term when we end up with a web standard that is actually defined by a single implementation: It becomes very hard for anyone else to implement the standard interoperably, or for the standard to evolve by design rather than by accident. Programming languages are the most complicated standards of all. SQL is good, but Mozilla thinks it's better to give up the advantages of embedded SQL for a lower-level API that is more standardizable, and doesn't add another language to the web stack. (The language we have now - JavaScript - is just starting to be truly interoperable itself.) IndexedDB can and will be backed by SQLite, and the SQL language can be built back on at the JavaScript layer where it will be portable to both SQLite- and non-SQLite backends. ActiveJS already includes a SQL parser/compiler in pure JavaScript for its in-memory datastore: http://activerecordjs.org/ http://activerecordjs.org/