(In a grumpy old man's voice) Back in my day, we rendered all the pages on the server, and we liked it! Times are changing and we are seeing a massive ground swell in client-side templating frameworks. At their heart, they're pretty much all the same; in that they take JSON data and apply an HTML based template contained within a script tag.

If you know what JSON is, skip this paragraph. I spent a little time last chapter discussing this, but just in case you skipped ahead and don't know, JSON is JavaScript written in such a way that it can be used as a data exchange format. It's more efficient than XML and can be read natively by all modern web browsers. Web browsers can even request JSON data across domains using JSONP, or JSON with padding. For more on JSON, read http://en.wikipedia.org/wiki/JSON. For more on JSONP, read http://en.wikipedia.org/wiki/JSONP. Bear in mind that the responding server needs to allow JSONP or this won't work.

All these client-side libraries...