The terminology in the article is a bit confusing but if "backgrounded" is intended to mean "apps that are hidden by the Hide command", there is a way to represent that with a hidden preference:<p><pre><code> defaults write com.apple.dock showhidden -bool true
killall Dock
</code></pre>
When an application has been hidden its Dock icon is then given a semi-transparent, faded appearance.<p>Also, although Mac OS X Lion changed the Dock so that <i>by default</i> there is no difference between running and not running, using System Preferences (Dock pane) the "Show indicator lights for open applications" setting can be turned back on.