What is it?
A language used for scientific and mathematical computing. Though limited in many ways, it is faster than upstarts like C and C++ at certain kinds of calculation. There is a huge library of functions which have been hammered to maximum efficiency over nearly 50 years.
Fortran is short for Formula Translator. If not the first high-level language, it is certainly the oldest surviving.
Where did it originate?
At IBM in the 1950s. Turing award winner John Backus designed a language to improve the performance of the IBM 704, and make programming quicker and easier.
Fortran was released commercially in 1957. Soon every major computer manufacturer had a version, but while many powerful new functions were developed, they could not be shared because of lack of compatibility. The America National Standards Institute took over in 1966 to establish the first-ever standard for a programming language. Subsequent major releases were defined by the standards body in 1977, 1990 and 1995.
What is it for?
Fortran is the probably the world's most widely used programming language for numerical applications. While subsequent releases have added features and functions to be found in other high level languages, its unique selling point remains its ability to handle matrix and vector calculations.
What makes it special?
In part Fortran's longevity is due to the huge legacy of applications which no-one has the time or money to rewrite in a more modern language. They work, so why bother?
Because of the early intervention of standards bodies, Fortran applications are universally portable. New releases have included older ones as subsets (Fortran77 in Fortran90, for example), which ensures forward compatibility, although it has also meant some pretty clunky stuff has survived.
A contributor to one of the formidably well-informed Fortran newsgroups comments, "It is not that it is a particularly great language (it is not - it is horrific), but there is a large mass of very good subroutine libraries out there, and no other language has compilers which are so good at optimising numerical code."
How difficult is it?
Fortran is less complex than C or C++, and easier to learn, assuming you have the required mathematical aptitude. Universities sometimes recommend Fortran to science students as an introduction to programming.
Where is it used?
Fortran is often used for numerical computation in applications built in Ada, C and Java.
Not to be confused with
TV game show, Wheel of Fortran.
What does it run on?
IBM, Intel and Compaq all supply Fortran compilers, and there are products for all versions of Unix and Linux, Windows and Macintosh. There are versions for parallel computers, such as High Performance Fortran (HPF), and for Cray supercomputers.
Few people know that
The 1962 Mariner 1 Venus mission was aborted, and the probe destroyed, because of a single error in a line of Fortran code.
What's coming up?
Fortran 2000. The draft standard is out for comment now, and commercial versions should be available by 2004.
This was first published in November 2002