Why doesn't kill work?

[William Wilson]

Zombie processes are spawned by a parent process that terminates before
receiving the childs signal that they have completed.  The Zombie is
waiting on acknowledgement from the parent process, thus they run
forever, or until the next reboot or someone kills them.  

They WILL NOT go away after the parent process dies.  This was
incorrectly stated in a previous email.  

If you are programming this, you can turn off the signaling of the
parent/child process to make the child not wait until the parent
responds and the child will do it's thing, then cleanly exit.  This also
frees up the parent to go about something else, rather than waiting on
the child, which may not complete.