This paper has described silicone rubber, its first commercial development in 1944, and its technological progress since then. Pioneering research on silicon opened the door to the development of silicone polymers and silicone rubber. The substitution of two methyl groups on silicon was present in the first examples of silicone rubber and still is the predominant organic group in commercial silicone rubber today. Silicone rubbers have filled a need in the marketplace because of their combination of unusual properties not found in other rubbers. The alternating inorganic main-chain atoms of silicon and oxygen, and the two pendant organic groups, primarily methyl, provide strong chain bonds, backbone flexibility, ease of side-group rotation, and low “inter” and “intra” molecular forces. This molecular makeup and properties thereof are primarily responsible for the observed performance of silicone rubbers. Many significant advances in silicone rubber have been discussed in chronological sequence to ...