Please be aware that this is a first draft of the API. I will improve it and add more features over the next weeks and months. Any support and feedback from developers helps me to make it better. If you've got questions, just send me an email: firstname.lastname@example.org
All methods return JSON. It has quickly become the most common format for APIs all around the web and it is very easy to handle - either for you and for me. Please get in contact if you urgently need some other format.
If you need to add a custom callback to any call (for JSONP for example), just add callback=yourcallback to the query.