The C programming language was created in the early 1970s as a system implementation language for Unix. It evolved from BCPL and became one of the dominant languages used today. The development of C was closely tied to the development of Unix, with major advancements happening in 1972 and between 1977 and 1979. The first widely available description of the language was published in the middle of the 1980s. C was officially standardized in the 1980s and gained wider use beyond just Unix systems. BCPL, B, and C are all procedural languages oriented towards system programming. They are close to the machine and rely on library routines for interactions with the operating system. The B language was created by Ken Thompson as a system programming language. It was a simplified version of BCPL and had no types. B was later rewritten in itself and evolved into C. C added features like generalized assignment operators, the ++ and — operators, and introduced a more conventional syntax for strings and arrays. The early versions of B and C were implemented as threaded code, an interpretive scheme for the PDP-7 Unix system.
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