Matthew Weier O'Phinney has posted the first part of a new series he's been working on about creating RESTful APIs with the help of Zend Framework v2. In this part, he looks at things like the "Richardson Maturity Model" and "Hypertext Application Language" as parts of development of the API too.
RESTful APIs have been an interest of mine for a couple of years, but due to circumstances, I've not had much chance to work with them in any meaningful fashion until recently. Rob Allen and I proposed a workshop for PHP Benelux 2013 covering RESTful APIs with ZF2. When it was accepted, it gave me the perfect opportunity to dive in and start putting the various pieces together.
After going over the "Richardson Maturity Model" for the REST structure he spends the rest of the post looking at HAL ("Hypertext Application Language") structure and examples. He mentions the media types it uses, how it handles links between resources and how to embed a resource into the resulting response.