This is the EXPERIMENTAL, bleeding edge of Drigg.
The main difference is that Drigg will basically be split into several, smaller, more manageable modules. This is very important because Drigg 1.x right now is one big fat 6000 line module...
Note:
Imagemenu by default use the same output style like core Drupal menu. Markers that you see left to menu items are background images. Use "background" style property to manage them (see imagemenu.css).