C is a structured programming language. It is also known as function orientated programming language. C programming language was developed in the year of 1972 by Dennis Ritchie at Bell Laboratories in the USA (AT & T).

In the year of 1968, research was started by Dennis Ritchie on programming languages like BCPL, CPL. The main aim of his research was to develop a new language to create an OS called UNIX. After four years of research, a new programming language was created with solutions for drawbacks in languages like BCPL & CPL. In the year of 1972, the new language was introduced with the name “Traditional C”.

The name 'c' was selected from the sequence of previous language ‘B’ (BCPL) because most of the features of 'c' were derived from BCPL (B language).

The first outcome of the c language was the UNIX operating system. The initial UNIX OS was completely developed using 'c' programming language.

The founder of the ‘C’ language, Dennis Ritchie is known as “Father of C” and also “Father of UNIX”.

The c programming language is very popular because it is reliable, simple and easy to use and it is the base for almost all the other programming languages.

The following are the language before ‘c’ & various versions of ‘c’.

1. CPL (Common Programming Language)

The CPL was invented by Martin Richards at the University of Cambridge in the early of 1960s.

2. BCPL (Basic Combined Programming Language)

The BCPL was invented by Martin Richards at the University of Cambridge in the year of 1966. It was a popular programming language at that time. BCPL allows the user, direct access to the computer memory. BCPL is the extension of CPL.

3. B Language

B language is derived from BCPL. It was introduced in the year of 1969 by Ken Thompson and Dennis Ritchie at Bell Laboratory, USA. The B language is similar to BCPL.

4. C Language

C language is derived from the B language. It was introduced in the year of 1972 by Dennis Ritchie at Bell Laboratory, USA. The C language was mainly developed to create an operating system called UNIX. The name C is given based on the previous language B and BCPL. Ninety percent of the UNIX operating system code is written in C language. During the 1970s, the C language became a very popular programming language. Many universities and organizations began creating their version of C language for their respective projects. So, C language has got many variants at that time. Later it was standardized.

5. ANSI C (C89)

In the year of 1983, the ANSI (American National Standards Institute) formed a committee to frame standard specifications for the C language. In the year of 1989, this committee introduced a standard version of C with the name "ANSI C" with standard library files. The ANSI C is also called as C89 in short form.

6. C90

In the year of 1990, the ANSI C was got ISO (International Organization for Standardization) standardization with the inclusion of a few new features like new library files, new processor commands. And it was also added with keywords const, volatile and signed, etc... ISO standardized ANSI C as ISO/IEC 9899:1990. This version is called as C90 in short form.

7. C99

In the year of 1995, many new features were added to the C90 to create a new version of it. This new version of C was got ISO standardization in the year of 1999 with the name ISO/IEC 9899:1999. In the short form, it is called as C99. Later C99 became the official standard version of C.