Rendering interactivity via custom JSON tiles
A new output renderer has just landed in mapnik trunk, called the grid_renderer.
This has been a very interesting and fun project to work on. I encourage you to check it out! It is powering the hover-able features in the latest TileMill 0.2.0 release and more details can be found on the trac wiki.Posted by Dane Springmeyer on 23 May 2011.