how drag&drop works on web applications like "Pivotal Tracker"
<p>could anybody give me information about how works JavaScript based on drag&amp;drop tabs like the ones used in Pivotal Tracker?</p>

<p><a href="https://www.pivotaltracker.com/" rel="nofollow">https://www.pivotaltracker.com/</a></p>

<p>I would like to know the technology behind it, and how it works when you drop the tab into a new view, how its state and variables changes, or how it interacts with the back-end via JSON.</p>

<p>thank you very much in advance</p>
