Inventor of the Week Archive
for a different Invention or Inventor
C Programming Language
A true trailblazer in the field of computer technology, Dennis
MacAlistair Ritchie, born on Sept. 9, 1941 in Bronxville,
New York, is credited with the 1972 creation of one of the
world’s most popular programming languages, “C.”
Ritchie attended Harvard University where he achieved an
undergraduate degree in physics in 1963, and a doctoral degree
in applied mathematics in 1968. His father, Alistair Ritchie,
had spent many years working for Bell Labs, and the younger
Ritchie followed him there in 1967, joining the Bell Labs
Computing Sciences Research Center.
The following year Ritchie began working on a joint project
involving Bell Labs, GE and MIT. The aim of the “Multics”
effort, which stands for Multiplexed Information and Computing
Service, was to develop a general-purpose computer operating
system. Earlier systems were incompatible with one another
and designed with singular or limited purposes and tasks in
mind; interoperability was virtually impossible.
For his part, Ritchie helped to design a compiler for the
language they were using at the time, BCPL, (for Basic Combined
Programming Language), for the Multics mainframe machine.
British computer scientist Martin Richards developed BCPL
in 1966. Ritchie also wrote a compiler for ALTRAN, a language
used for symbolic calculation. A “compiler” is a computer
program that translates a high-level language program, or
source program, into machine language instructions, also called
the object, target, or output program.
A colleague of Ritchie’s at Bell Labs, Kenneth Thompson,
adapted BCPL into “B” in 1969, as the pair went to work to
create the Unix operating system, born in 1970. Early
in the development of Unix, Ritchie began modifying B, adding
data and syntax characteristics that turned B into the famed
C in 1972.
Unix components were at first written in B, but eventually
rewritten in C, culminating with the kernel in 1973. Thus,
C became the foundation for the system’s portability. Unix
was easier to move onto new computers because it was unnecessary
to translate the entire operating system for each new computer’s
assemble language by hand. It also made Unix—and therefore
any machine it was installed into—easily customizable, especially
since C was a high-level language that was relatively easy
for a skilled programmer to learn.
Many did learn C, and their subsequent modifications to
the Unix operating system have made it even more useful and
efficient. C became widely used in other contexts as well,
in computers of all sizes and for all types of purposes. U.S.
and international standards were eventually established, and,
of course, C served as the basis for C++, designed by Ritchie’s
colleague, Bjarne Stroustrup. C also served as the basis for
systems such as BSD and Linux have hit the mainstream as well.
Ritchie has been recognized with a number of awards and
honors for his achievements and continues to garner praise
for his ongoing work. He was named Bell Labs Fellow in 1983,
and, also that year, he and Thompson won the prestigious Turing
Award for their work Unix and general operating systems. He
was elected to the U. S. National Academy of Engineering in
In 1990, Ritchie became head of System Software Research
Department in Bell Labs’ Computer Sciences Research Center.
His group created the Plan 9 operating system, released in
1995; and the Inferno operating system, unveiled in 1996.
In 1999 he and Thompson were both honored with the U.S. National
Medal of Technology for their joint efforts in the development