Forever Fortran: digital language renewed.

Few issues arouse the passions of computer programmers more than the relative merits of different programming languages, and the veteran language Fortran has certainly endured its share of criticism over the years. Nonetheless, Fortran remains the stalwart workhorse of scientific and engineering computation, retaining its appeal by periodically putting on a fresh face.

The latest version, dubbed Fortran 90, was approved last month as the international standard for Fortran by the International Organization for Standardization, based in Geneva, Switzerland. This new edition extends and replaces Fortran 77, adding a number of features that make it more flexible for scientific applications and better suited for running on computers consisting of dozens or even thousands of processors.

Fortran 90 offers "greater safety, expressive power and convenience" than its predecessor, says John K. Reid of the Rutherford Appleton Laboratory in Didcot, England. Reid, who served on the committee that established the Fortran 90 standard, described some of the new version's advantages this week at the International Conference on Industrial and Applied Mathematics, held in Washington, D.C.

Developed in the 1950s, Fortran was the first programming language widely used to solve scientific and engineering problems. Equipped with a set of carefully defined commands and symbols, it permitted computer programmers to escape the tedius, error-prone chore of writing out instructions directly in the language of a computer -- that is, as strings of ones and zeros.

Fortrain 90, the result of a 14-year effort, brings the language up to date. It contains new instructions that allow the manipulation of arrays, such as tables of measurements, as single units. It also makes it easier for users to switch from one level of numerical precision to another. At the same time, the revised version retains all the features necessary to ensure that existing software written in Fortran 77 still works.

One company has already developed the first compiler that meets the Fortran 90 standard. Written by Malcolm J. Cohen and his colleagues at Numerical Algorithms Group Ltd. in Oxford, England, this special computer program translates statements written in Fortran 90 into the computer language C, which can then be transformed into instructions a computer understands. Additional Fortran 90 products are in the works.