Mongodb client side javascript api
Looks like the site uses REST-like AJAX interface, but I am certain that it does not access any MongoDB instance directly or even indirectly via some bridge.
Thinks twice before applying this pattern: how will you enforce security? Are you aware of AJAX limitations? If you really know what you are doing, the official documentation points to few useful resources:
Sleepy Mongoose (Python) is a full featured REST interface for MongoDB which is available as a separate project.
MongoDB Rest (Node.js) is an alpha REST interface to MongoDB, which uses the MongoDB Node Native driver.
Simple REST Interface The mongod process includes a simple read-only REST interface for convenience. For full REST capabilities we recommend using an external tool such as Sleepy.Mongoose.
Having a REST bridge and managing the same origin policy you can easily access MongoDB directly using AJAX calls and JavaScript.