From Moose Factory:
What the "Cool Unmount Volume" extension does is to send a "quit" message to any application launched from the volume (like a zip volume, a cd-rom, a diskette, etc.) you want to eject, so that you don't get annoyed by this message any more. What happens with launched applications on that volume is merely the same as what happens when you shut down your Macintosh.
What's new in this version:
Cool Unmount Volume is now a Control Panel
You can now drag and drop any volume or disk onto CUV in order to eject it.
You can disable the display of the startup icon
It features starting Mac OS X compatibility.
Disk images could not be ejected with drag and drop onto CUV. This has been fixed.