JavaScript – Database API

KeyValue – localStorage (IE 8, Firefox 3.5, Safari 4)
http://simplehomepage.appspot.com/sql/local-storage.htm

SQLite – openDatabase (Safari, Firefox 3.51, Chrome)
http://simplehomepage.appspot.com/sql/open-database.htm

SQLite – Kripken SQL.js (compiled through Emscripten)
http://simplehomepage.appspot.com/sql/kripken-sql.htm