Fortran's Modern Renaissance: Why Developers Are Revisiting the Original High-Performance Language

In an industry perpetually chasing the "next big thing" in programming languages, developer curiosity is taking an unexpected turn: backward. As chronicled in a recent technical exploration, engineers are rediscovering Fortran – IBM's 1957 creation originally dubbed FORmula TRANslator – not as a relic, but as a living language with unique strengths in scientific computing and high-performance workloads.

The Evolving Colossus

Born in the punch-card era, Fortran has undergone significant modernization through standards like Fortran 90 (which introduced free-form syntax), Fortran 2003, and the current Fortran 2018. Developers today typically use .f90 file extensions to leverage free-form layout while accessing features from newer standards. As noted in Fortran community discussions:

"The .f90 suffix means that the source code is free format, not that the code conforms to the Fortran 90 standard. Code that uses the .f90 suffix can use features from any Fortran standard" (Fortran Discourse).

Modern Syntax: Beyond the Stereotypes

Contrary to expectations of archaic syntax, modern Fortran offers straightforward structure:

program hello
  print *, 'Hello, world!'
end program hello

Key observations from hands-on experimentation:
1. program/end program bookend executable code
2. print * outputs to STDOUT (the asterisk denotes default output)
3. SCREAMING_CASE has given way to snake_case conventions
4. implicit none is mandatory for safety, disabling legacy implicit typing where variables starting with I-N defaulted to INTEGER and others to REAL – a system that spawned the classic joke: "GOD is REAL, unless declared INTEGER"

Building Practical Applications

A simple calculator demonstrates Fortran's practical workflow:

program calculator
  implicit none
  real :: x, y, answer
  character(1) :: choice

  print *, 'x:'
  read *, x
  print *, 'y:'
  read *, y

  print *, '+, -, *, /:'
  read *, choice

  select case (choice)
    case ('+')
      answer = x + y
    case ('-')
      answer = x - y
    case ('*')
      answer = x * y
    case ('/')
      if (y /= 0.0) then
        answer = x / y
      else
        print *, 'Error: Division by zero!'
        stop
      end if
    case default
      print *, 'Invalid operator'
      stop
  end select

  print *, 'Answer:', answer
end program calculator

This example highlights:
- Explicit typing with real and character
- Terminal I/O via print * and read *
- Control flow with select case (cleaner than nested IFs)
- Error handling for division by zero
- Compilation via gfortran -o calculator calculator.f90

Why Fortran Endures

Beyond academic curiosity, Fortran maintains vital niches:

Numerical Prowess: Optimized array operations and mathematical notation alignment
HPC Heritage: Battle-tested in supercomputing environments
Performance: Minimal abstraction overhead for computationally intensive tasks
Modernization: Ongoing standard updates and improved tooling

Even prominent tech voices are reconsidering Fortran – ThePrimeagen recently retracted previous criticisms, acknowledging renewed interest in the language. As scientific computing faces increasingly complex challenges in climate modeling, quantum simulation, and financial analytics, Fortran's blend of raw number-crunching efficiency and modern syntax updates positions it as an unexpectedly relevant tool. The journey continues with advanced topics like parallel computing via Coarray Fortran and C interoperability awaiting those who venture beyond "Hello, World."

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