Huge number of anonymous.xpcd?
From Apple's launchctl manual page (emphasis added):


  Note that you may see some jobs in the list whose labels are in
                the style "0xdeadbeef.anonymous.program".  These are jobs which
                are not managed by launchd, but, at one point, made a request to
                it.  launchd claims no ownership and makes no guarantees regarding these jobs. They are stored purely for bookkeeping purposes.