Turbodrag pumps, i.e. molecular pumps with a bladed section followed by a drag section on a common shaft, have become the most popular high vacuum pump in the last 12 years, as they tolerate backing pressures approximately a hundred times larger than pure turbopumps. The paper reviews various technologies for turbodrag pumps in terms of the merits and limitations of their design principles. This covers rotor dynamics aspects, response to thermal loads, maximum rated backing pressure and throughputs, compression ration versus size as well as mechanical design considerations and potential future developments.