Less Is More

When it comes to representations returned from a RESTful API, is there a preferred format? If JSON better than XML? More often than not, JSON is the preferred representation format because Ajax web applications are usually making the API requests. And when it is some other application making the request, it is usually trivial to make use of the returned data.

What about returning HTML as a RESTful representation? Isn't it as useful as JSON or XML? I would like to think so, just as long as it is consistent and simple. For instance, returning HTML lists is probably just as easy for clients to parse as retuning some other format. The added benefit is that HTML can be inserted directly into a browser. It can also be styled any any way imaginable.

Using HTML is less because it involves less work on the client end in most cases. It is more because it offers more flexibility.