Taskbar button "Bins"

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Windows

Taskbar

grouping

I stumbled across something very interesting http://www.1upindustries.com/Bins/Default.aspx[^].

Is it an application that is pinned to the bar and renders it's icon based on its contents, then also renders a hover menu with thumbnail to simulate the windows taskbar? What about the handles above the buttons? how do they prevent the running program from displaying in the taskbar with a separate icon?

For the life of me I cant figure out how they accomplish it without replacing the taskbar, Any Ideas?