Snow Leopard comes with subtle changes that refine the Mac OS X experience, minimize application windows to application icon is one of them.
When you minimize a window under Mac OS X, the default behavior is to shrink the window into the thumbnails of the dock, one icon per window. This leads to irritating Doc clutter if you have a number of minimized windows.
![Snow Leopard Dock 1](http://sanziro.com/wp-content/uploads/2009/10/snow-leopard-dock-1.png)
Snow Leopard has an additional entry “Minimize windows into application icon” in its System Preferences > Dock settings where you can select to hide minimize windows into application icon instead of thumbnails of the dock.
![Snow Leopard Dock 2](http://sanziro.com/wp-content/uploads/2009/10/snow-leopard-dock-2.png)
You can accessed minimized windows as usual from the application’s Window menu or from the icon menu by Control-Click on the app icon on the Dock. Minimized windows also appear below at the bottom in Dock Expose when you click and hold the app icon on the Dock. Similarly minimized windows appear at the bottom when you activate Expose.