History of the C programming language dates back to 1969.

  • 1969 Ken Thompson started to develop a language called B (kind of stripped down version of BCPL) around 1969 1.
  • 1971 Dennis Ritchie started to improve the B language and called this new language New B or NB, in short.
  • 1972 After several modifications to B, Dennis Ritchie decided to give a distinct name to this modified B language and created the C language in 1972.

But why C? It is believed that Ritchie selected the letter C (the next letter after B) because the language actually was derived from the B programming language2.

  • 1978 6 years after the birth of C, in 1978, Brian Kernighan and Ritchie published The C Programming Language book. The version of C explained in that book is known as K&R C. This is one of the first programming books having the classical Hello World example. The C version described in this book can also be called as C78 although it is not very common.
printf("hello, world\n");
  • 1989, 1990 Around 1989 and 1990, ANSI and ISO began to standardize the language and they created C89 (ANSI C) and C90 (ISO C). In practice, all four of them refer to the same language. Up until the this first standardization process, The C Programming Language book was the de facto standard manual for the language.
  • 1999 Several modifications were added to the language after 1990. The second major revision was published in 1999 as C99.
  • 2011 The third major revision C11 was published in 2011.
  • 2017 C17 was published in 2017 and it didn’t introduce new features to the language and only did some technical corrections and clarifications to specifications in C11.
  • 2023 (?) The next version after C17 is called C2x. The new version is expected to be published in 2023 as C23 3 4.

UNIX and C

UNIX and C are very tightly coupled projects. We can say that C language is by-product of UNIX project. In 1973 UNIX was rewritten in C. I would like to quote directly from Quora:

UNIX and C are two sides of the same coin. C was invented solely to write the UNIX kernel. UNIX is the OS that went viral because of C.

You can look at History of Unix for further details.

Brian Kernighan talks about C and the book: