JSonduit is a service that can turn practically anything on the web into a JSON feed that any website or mobile app can consume. A JSON conduit, if you will.
Feeds are created from one or more source URLs and a custom transform, written in JavaScript, that can manipulate the data before the feed is served.
JSonduit also provides a hosting service for web widgets so that any site can easily display JSonduit feeds. In fact, the recent/popular lists you see below are widgets served by the JSonduit service; all done in a couple of lines of JavaScript (go ahead, view the page source!).