Fernando Corbato

Fernando Jose Corbato was an American computer scientist who spent his career at MIT after earning a PhD in physics there in 1956, becoming a leading pioneer of time-sharing operating systems that let multiple users share a single computer resources simultaneously. Corbato led development of the Compatible Time-Sharing System, first demonstrated at MIT in 1961, one of the earliest working time-sharing systems, and he is credited with the first use of passwords to control access to files on a large shared computer system. He went on to lead the Multics operating system project, adopted commercially by General Electric and later Honeywell, which pioneered concepts including hierarchical file systems, security rings, access-control lists and dynamic linking that became standard features of later operating systems including Unix. Corbato received the ACM Turing Award in 1990 for his pioneering work organizing the concepts and leading the development of general-purpose, large-scale time-sharing and resource-sharing computer systems.