SQLite compiled to javascript
For the impatients, try the demo here: http://kripken.github.io/sql.js/examples/GUI
sql.js is a port of SQLite to Webassembly, by compiling the SQLite C code with Emscripten. It uses a virtual database file stored in memory, and thus doesn't persist the changes made to the database. However, it allows you to import any existing sqlite file, and to export the created database as a javascript typed array.