Over the past half-century, Siemens/Westinghouse systematically developed the cathode-supported tubular solid oxide fuel cell (SOFC) technology and demonstrated the world's first highly efficient, longest running 100-kWe class solid oxide fuel cell/combined heat and power (SOFC/CHP) system and the first highest-efficiency, 220-kWe class pressurized SOFC/gas turbine (PSOFC/GT) hybrid system based on this technology. This review provides a broad overview on this technology from the perspectives of materials, manufacturing, cell design, system integration and electrical testing. It starts from the basic facts of a SOFC, where the working principle, advantages, types and applications of SOFCs are discussed. It then focuses on cathode-supported tubular SOFCs, one important type of SOFC design, by providing detailed technical information on engineering innovations, materials advances, manufacturing processes and electrical performance of Siemens/Westinghouse's cylindrical and flattened ribbed tubular cells. The review concludes with a high-level summary of the SOFC systems manufactured and demonstrated by Siemens/Westinghouse in the past few decades.