The osmic projector was a technology used by the Sontarans, originally designed by the Kaveetch. It was available to the Sontarans from at least the 13th century, but had been in existence since their creation.
When the Sontarans turned against the Kaveetch to prevent their creators exposing their weaknesses, a few hundred Kaveetch escaped their deaths by using the osmic projector to send themselves into the future, eventually arriving on Earth in the 1800s. They spread out around Earth during this time, but were eventually rediscovered and most of them killed by a Sontaran fleet, with the last two survivors being taken to a new planet by the Sixth Doctor (AUDIO: The First Sontarans).
In the 13th century, (TV: The Sontaran Experiment) Commander Linx used an osmic projector to travel into 20th century to procure advanced technology and skilled personnel to assist him in repairing his vessel. Use of the projector left a ghost-like figure of the projected being for some minutes after its use, traces of which could be illuminated by a black light. Use of the projector also released delta particles, which was detectable by specialised equipment, such as a rhondium sensor. (TV: The Time Warrior)
In 1941, a group of Sontarans belonging to the Eighth Battle Fleet scanned for temporally shielded devices using an osmic projector. Upon activating it, the Doctor's TARDIS was caught in the "temporal tuna net" and drawn off course. Later, the Twelfth Doctor used a Sontaran osmic projector to send Heinz Bruckner's control device for the Warsong through time to prevent Bruckner from controlling the Warsong. (COMIC: The Instruments of War)
Osmic projectors were also used by the Sontarans to secure the human outpost on Agni, the third moon of the gas giant Indra in the Unulkalhai system. In this capacity, the Projector operated like a traditional transmat device, although the Fifth Doctor stated that the principles behind the system were based on quantum tunnelling rather than typical matter transmission. The Doctor later used the projector to escape the Sontaran garrison on Agni. Later, the Sontarans planned to use an osmic projector to retrieve an assault team sent to re-capture the Doctor and his allies. This mission failed when the entire assault team was killed in action by coronic acid. (PROSE: Lords of the Storm)