| Basic FORTRAN | ⊕ 1964 | ↓ ↑ ⊕ Numerical Scientific | FORTRAN IV standard | ⊕ United States | |
| BTL Fortran | ⊕ 1967 | ↓ ↑ ⊕ Numerical Scientific | FORTRAN IV standard | ⊕ United States | Bell labs Fortran IV |
| DEFT | ⊕ 1973 | ↓ ↑ ⊕ Numerical Scientific | FORTRAN IV standard | ⊕ Canada | Structured FORTRAN |
| DELtran | ⊕ 1975 | ↓ ↑ ⊕ On-Line | FORTRAN IV standard | ⊕ United States | Fortran interpreted to DEL |
| FORTRAN IV | ⊕ 1962 | ↓ ↑ ⊕ Numerical Scientific | FORTRAN IV standard | ⊕ United States | first major release of FORTRAN |
| RC-Fortran | ⊕ 1968 | ↓ ↑ ⊕ Numerical Scientific | FORTRAN IV standard | ⊕ Denmark | Fortran for the RC 4000 |
| WATFIV | ⊕ 1969 | ↓ ↑ ⊕ Numerical Scientific | FORTRAN IV standard | ⊕ Canada | Waterloo FORTRAN 2nd version |
| WATFOR | ⊕ 1966 | ↓ ↑ ⊕ Numerical Scientific | FORTRAN IV standard | ⊕ Canada | WATerloo FORtran |