  We give a broad overview of the history of microwave superconductivity and
explore the technological developments that have followed from the unique
electrodynamic properties of superconductors. Their low loss properties enable
resonators with high quality factors that can nevertheless handle extremely
high current densities. This in turn enables superconducting particle
accelerators, high-performance filters and analog electronics, including
metamaterials, with extreme performance. The macroscopic quantum properties
have enabled new generations of ultra-high-speed digital computing and
extraordinarily sensitive detectors. The microscopic quantum properties have
enabled large-scale quantum computers, which at their heart are essentially
microwave-fueled quantum engines. We celebrate the rich history of microwave
superconductivity and look to the promising future of this exciting branch of
microwave technology.
