The Editorial

This Special Issue is dedicated to Medipix and Timepix semiconductor radiation detectors whose origins lie in the R & D for the semiconductor tracking detectors of the Large Hadron Collider at CERN. The issue covers developments starting with the early idea of photon counting readout first implemented in the Medipix ASIC right up to the advanced Timepix ASICs, and their applications in different fields of science, industry and medicine, stretching all the way from charge particle tracking in High Energy Physics to molecular spectroscopy.