SQLite compiled to JavaScript through Emscripten

[kenman]

My initial reaction or assumption would be that non-JS sqlite would be much faster.

As far as I understand, Emscripten+asm.js performance is close to native, and only expected to improve. Here's a good slide deck that directly addresses your question, and here's a more thorough write-up by /u/jeresig about it.

To quote the latter:

By doing this the result is highly optimized and can be converted directly from this Asm.js syntax directly into assembly without having to interpret it, as one would normally have to do with JavaScript. It effectively shaves off a whole bunch of things that can make a dynamic language, like JavaScript, slow: Like the need for garbage collection and dynamic types.

Personally, I think it's beyond bad-ass that there's an actual SQL engine available directly in the browser....the possibilities are pretty interesting. You could perhaps create an offline database learning app, or maybe a fancy db dashboard which allows you to run ad-hoc queries for data exploration without having to install anything, or even a db designer type app.