QuitsApps is a utility for quitting groups of applications. You can either use "quit flags" to mark a collection of applications for immediate termination, or create a schedule for quitting applications at different times. Subsequently you can relaunch the last set of terminated applications.
This functionality is also available as a menu in the system menu bar.
QuitsApps is part of the Limit Point Software Utilities Bundle : http://www.limit-point.com/Utilities.html. Purchase a Utilities password to activate all the utilities, including QuitsApps. Upgrades are free, new utilities are included.
QuitsApps initially runs for about ten days without a permanent password.