C was originally developed in the early 1970s by Dennis Ritchie at Bell Labs to write the UNIX operating system. Previous languages like FORTRAN and B were insufficient for this task. Ritchie developed C between 1971-1973 to create a language that was better suited to writing UNIX. UNIX was then rewritten in C, and even the UNIX kernel was rewritten in C in 1973 on a PDP-11 computer. C became widely popularized after Ritchie and Brian Kernighan published their book "The C Programming Language" in 1978. C has since evolved through various standards, with Dennis Ritchie considered the father of C for his approach in developing UNIX with shared computing resources for multiple users.

1. BY- VISHWESHWAR MANAW
TO- DR. RAJESHWARI TRIVEDI
(CORDINATOR – B.SC. IT)

3. ALGOL >> BCPL >> B >> C
ALGOL was the first Programming Language to use a
block structure made the basis of Modern Languages as
it gave the concept of Structured Programming.
BCPL was developed by the Martin Richards in 1967
highly influenced the B language which was developed
by Ken Thompson in 1970 at Bell Labarotries for the
first Unix System.
FACT : BCPL and B are “type less” languages.

4. • C was originally developed for writing the UNIX
operating system for the DEC PDP-7 Super-
computer. UNIX was written first in language
FORTRAN & B where B was used mostly but B
did not support Data Structures and data types
were also expressed in Machine language.
• So, Ritchie along with his colleagues developed C
during 1971-73 for writing the UNIX.
• UNIX was rewritten in the C, even UNIX Kernel
was also rewritten in C in 1973 on DEC PDP-11.

5. • Dennis Ritchie & Brian Kernighan documented the
creation in the form of a book called “The C
programming language”. After then C was
popularized more and was called as ‘K & R C’.
• C came into change when ANSI(American National
Standards Institute) formed a committee in 1983
for its standardization and C got its new version
ANSI C or C89 in 1989.
• C was certified by the International Organization
for Standardization (ISO) in 1990 and called as
ANSI/ISO C.

6. • Overtime C evolved with some new features in 1999
by a Standardization Committee and called as C99
though many compilers does not support this version
of C.
• From all apart the contribution of many scientists in
the development of C but Dennis Ritchie is considered
as the Father because of his approach of developing an
Operating System having the features of sharing the
common computing resources with multiple
users made to the birth of a Robust language
C!

7. Some Facts about the Evolution of C language
• Before the Invention of C Ritchie was involved in a
project of MULTICS at Bell labs. MULTICS was an
operating system which can allow multiple users but
was stopped by the Bell labs due to overweighting of
its cost over benefits.
• UNIX was earlier named as UNICS (Uniplexed
Information and Computing Service) which was taken
from MULTICS (Multiplexed Information and
Computer Services). Later it changed to UNIX.

8. • C programs are written using block structure which it
got from ALGOL programming language. ALGOL also
gave the concept of Structured Programming.
• Although Brian Kernighan documented ‘The C
Programming Language’ with Dennis Ritchie but he was
not directly involved in the design of C. Though he
was the author of the famous “Hello World” program
and many other UNIX programs.