Trello is not only a very useful task management system, incorporating SCRUM board approach with HTML5 and an exceptional nice look and feel… now it also has a very elegant REST API.
Check it out…
https://trello.com/docs/
Here is a quick sample on how to retrieve the cards for the current user… using the Client.js JavaScript class that Trello is providing asn easy way to get started…
http://jsfiddle.net/nNesx/
They have opened up their development plans in the form of their internal development board…
https://trello.com/api
