Everybody loves JSON. (No, I don’t have any links to back that up.) And for good reason– browsers are fluent in it, it’s easy to generate, easy to parse and lightweight enough to make it the ideal way to communicate with web services.
JSONP (the P is for padding) is a well known technique to get around web browsers’ same origin policy. By circumventing the same origin policy, JSONP removes the need to do any server-side work to access cross domain resources. CORS obsoletes JSONP, but until it’s more widely implemented, JSONP will continue to have a prominent place in any web developer’s toolkit.
So there you have it, JSONP APIs. This has been post number three of five discussing the techniques and technologies used to build bearpanther’s instamap.