Wake Machine enables Time Machine to backup to a target that is sleeping. Without Wake Machine, such backups will fail because the remote disk cannot be mounted while the target machine is sleeping.

Wake Machine runs as a mock daemon on the client. When Time Machine initiates a backup, Wake Machine sends a magic packet to the target machine to wake it up if it's sleeping.

Caveats: If you're using an older Mac, the target machine must be connected via ethernet (the machine you're backing up can still be connected via wifi). New Macs support WOL via Airport.

For more information, visit http://www.freerobby.com/wakemachine

Wake Machine uses Pivotal Tracker to track stories and bugs. You can see the public tracker at http://www.pivotaltracker.com/projects/28564