I compiled a tool named "Beeper", which simply calls NSBeep() every second, in an infinite loop. I then loaded this job using launchctl: <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0"> <dict> <key>ExitTimeOut</key> <integer>5</integer> <key>Label</key> <string>beeper.plist</string> <key>ProgramArguments</key> <array> <string>/Users/jk/Documents/Programming/Builds/Debug/Beeper</string> </array> <key>RunAtLoad</key> <true/> </dict> </plist> As expected, my computer begins beeping. Note that ExitTimeOut = 5. Expected Result: My tool should get a SIGKILL and quit beeping after 5 seconds. Actual Result: My tool keeps executing until I kill it with other means. What's wrong? Thanks, Jerry Krinock