Process Watchdog Daemon

[Dave Smith]

I am looking for a watchdog daemon that monitors individual processes 
(given a pid file for each one), and restarts one if its pid is found to 
not be running. This is different than the typical watchdog, which would 
reboot the entire computer if a problem were found. Does this exist? I 
would also like for it to quit watchdogging a process if it continually 
crashes (i.e., if it is restarted N times in M seconds), or at least 
slow down on the restart interval. Any ideas?

--Dave