If you work with or on Fortran code and codebases, you are invited to participate. The organisers intend to publish the results, and the anonymised data, later this year.

The survey comes at a time when Fortran remains a cornerstone of modern science. Despite the sustained, highly-impactful contribution of Fortran over nearly 70 years, the international community—those who develop the language and those who use it in science and engineering—remains largely invisible to those outside the community. In some ways, the community remains invisible to itself too.

Fortran – a portmanteau of Formula Translation – is designed to concisely express mathematical formulations. This, and its native parallel model, makes Fortran a natural choice for many scientific and engineering applications. Created in the late-1950s, Fortran is the oldest third-generation programming language in active use and development today. The latest revision to the Fortran standard is Fortran 2023. Fortran is also the only programming language with a commitment to compatibility across all the revisions of the standard, e.g., allowing code written in Fortran 77 to compile and run with code written in Fortran 2023. And finally, Fortran is one of the few, if not the only, standardised language with a native parallel programming model.

Despite investment in many other languages and architectures over the years, Fortran and Fortran codebases are still crucial for many current scientific disciplines. As examples:

• 6 of the top-10 codebases running on the UK’s Archer2 HPC service are Fortran codebases: VASP, CASTEP, SENGA+, CP2K, NEMO, Met Office Unified Model.
• Table 1 provide indicative examples of active Fortran scientific codebases from the UK and internationally.
• Beliavsky actively maintains a list of several hundred Fortran scientific codebases and tools on GitHub.

Table 1 Indicative examples of groups in the UK and internationally invested in Fortran