The latest version of the ISO/IEC standard 1539 - 1:2004, informally known as Fortran 2003, was published in November 2004.

This standard is the culmination of almost a decade's work by representatives from the US, UK and other countries.

Fortran was designed to be easy for scientists and engineers to learn so that they could readily program their own problems on to a computer.

The development of the language has continued with these principles in mind while incorporating modern features, such as character strings and block IF statements in Fortran 77 and memory allocation at run-time and free form source format in Fortran 90.

Fortran 2003 includes several features to support object-oriented programming, a standard way of interfacing with C (previously different compilers required different approaches) and a standard way of accessing operating systems features.

In the UK Fortran users include the Meteorological Office, the Ministry of Defence, universities, research labs and other scientific institutions.

The information used to produce our daily television weather forecasts and longer term climatic predictions is produced by very large Fortran programs running on supercomputers.

Fortran is also used in the finance industry, which does complex calculations to analyse stock market and financial market data. At present the UK has three software companies producing Fortran compilers and tools.

Estimates suggest that there are several thousand organisations in Europe using Fortran applications, although not all of them are using Fortran to develop new programs. This is partly due to Fortran being seen as an old language whilst people want to be seen as modern, so C and C++ have moved to the fore.

Fortran champions believe that despite efforts to improve facilities for scientific calculations in C and C++, Fortran has a wider range and is better in important areas, notably for handling multi-dimensional arrays and very large data sets.

They also argue that Fortran is not only a safer language but also produces highly reliable programs that are easier to write and maintain.

The developers of the new standard were focused on ensuring that it would be compatible with an object-oriented approach that did not go overboard in this direction.

For example, Fortran 2003 avoids multiple inheritance, because it adds too much complexity for too little gain in expressive power. Likewise, Fortran's unique ability to handle massive data sets and array processing was kept intact by rejecting the tactic of making everything a polymorphic object, as in other languages.

The arrival of Fortran 2003 means that anyone planning a new development in a scientific domain should strongly consider using it. It is a language that has been redeveloped for the 21st century.

Peter Crouch is chairman of the BCS Fortran Specialist Group.


The BCS Fortran Specialist Group has been a UK focus for the development of the language since its formation in 1970.

The current conveners of the ISO WG5 committee responsible for the Fortran language and the BSI (UK) Fortran panel are both members of the Fortran SG committee.

For the last few years the group has provided financial support from the BCS's Specialist Groups Development Fund to enable several UK representatives to participate in international standardisation work who would not otherwise have been able to take part.

Fortran has been renowned for the efficiency of the code produced by the compiler since its development at IBM in the 1950s by a team led by John Backus.

Further reading

  • The 567 page Fortran 2003 standard is available in the UK from at £129 for BSI members and £258 for non-members 
  • Fortran 95/2003 Explained by Metcalf, Reid and Cohen (OUP)
  • The Fortran Company has links to free Fortran resources
  • The comp.lang.fortran discussion list covers many aspects of Fortran programming.