Beside the ability to start or open everything, QuickSilver also has the rights to finish it. This has something to do with scripting, as someone has built the script, appreciating them with using the script will be the most polite giveback.

QuickSilver reveals all invisible being

Deep hidden Application under the Dock will be revealed with a single script called 'Show All'. Call it up with QuickSilver, usually with acronym shall, perform the Run script (default setting) and all the invisible Apps will lose their invisibility.

Also QuickSilver can hide inactive Apps

This will be very useful, especially for them who need bunch of Apps to help their work. Use the same way as Show All but with different acronym, i.e. hot

QuickSilver assassinates all visible Apps

Being visible means more vulnerable than others, the same rule apply for QuickSilver. With 'Quit Visible Apps' script, QuickSilver kill all visible Apps. Apps, be careful of QuickSilver assassination. The acronym to call up this action script is qvapp