A little while ago, Vladimir Vukicevic wrote an excellent blog post outlining the reasons why he’s not a fan of exposing a specific implementation of SQL to Web Content.
I agree with everything he says in his post; I’ve also been a fan of CouchDB for some time. A CouchDB-like API seems like a nice solution to persistent storage on the Web because so many of its semantics are delegated out to the JavaScript language, which makes it potentially easy to standardize, as well as easy to learn for Web developers. Furthermore, CouchDB’s MapReduce paradigm also naturally takes advantage of multiple processor cores—something that is increasingly common in today’s computing devices.
To explore the possibility, I decided to spend some time prototyping a JavaScript implementation of CouchDB, which I’ve dubbed BrowserCouch. It’s intended to work across all browsers, gracefully upgrading its functionality when support for features like Web Workers and DOM Storage are detected.
Right now this is very much a work-in-progress and there isn’t anything particularly shiny to see; just the test suite and the semi-large data set test. In the future, it’d be great to make CouchDB’s Futon client work entirely using BrowserCouch as its backend instead of a CouchDB server, but that’s a ways away.
If you’d like to see some code samples of what the BrowserCouch API currently looks like, check out the annotated source code for the test suite. You can also read the primary source code documentation for more on BrowserCouch’s implementation. And if you’re interested in hacking on the code, the Mercurial repository is right here.