This report covers history and results of the long-term research directed at developing an absolute vector proton magnetometer based on the switching of bias magnetic fields. In recent years, the development of proton vector magnetometers achieved essential progress based on the application of the Overhauser effect providing stronger proton signal from smaller sensor size. Designs and metrology properties, which can be interesting to the experts in vector proton magnetometers and professionals of magnetic exploration and observatories, are presented.