Learn

FORTRAN (FORmula TRANslation) was the first high-level language, designed in 1957 by John Backus at IBM. Modern Fortran (Fortran 90 and newer) keeps the strengths — vectorized math, performance — and shed the column-numbered punch-card era.

program hello
    print *, "Hello, Fortran!"
end program hello

• program name ... end program name defines the entry point
• print *, ... — the * is a default format specifier (free-form output)
• Comments use ! (anywhere on the line)
• Statements end with newlines, not semicolons. Continuation uses &
• Identifiers are case-insensitive (Print = PRINT = print)

Reading stdin: read *, var reads one or more values, type-aware:

integer :: n
read *, n
print *, n * 2