In some sense, there are dialects within the Fortran standards themselves, including free form and fixed form as well as implicit none? and other variations of the implicit? statement.
Several independent dialects of Fortran have also been created over the years, including:
- EGTRAN (Egdon Fortran), a dialect of FORTRAN II? (1965)
- RATFOR—Rational Fortran Fortran 66-77? (1974)
- IFTRAN—a Structured Extension of Fortran Fortran 66-77? (~1974)
- ELF90—Essential Lahey Fortran 90
- F—a selected subset of Fortran 95
- Parametric Fortran – a Fortran program-generator generator that can produce extensions of Fortran