Ur-box
An Ur-box was a complex device of Time Lord design. It recorded events of a specific point in the timeline. It projected that data and information into the Time Vortex, sending false information to time scanners of time active factions. This allowed the users of the Ur-box to operate without being detected and so change a point in the timeline.
There were, however, several problems with the technology. It had a limited sphere of influence which necessitated that there would have to be no excursions outside the field. Events within the field needed to be match those of the Ur-text and so individuals were required to act out events from the "real" timeline.
Xenaria made use of an Ur-box during the events surrounding the breaching of the time loop surrounding Planet 5. (EDA: The Taking of Planet 5)