dpd(8) System Manager's Manual dpd(8)

dpdDisplay Port daemon.

dpd

The dpd executable is a daemon intended to listen for Command + F2 on the iMac to switch to external display input mode upon display port hot-plug. This feature is known as Target Display Mode. It disables display and idle sleep while in external display mode and launches an audio tool called dpaudiothru to capture audio input and route it into the mac unit. To go back to normal mac mode, unplug the display port or press Command + F2 again, which will restore all settings.

dpd should only be run via launchd.

/usr/libexec/dpd
The daemon
/System/Library/LaunchDaemons/com.apple.dpd.plist
The launchd configuration plist
February 18, 2009 Darwin