| Delta Prolog | ⊕ 1984 | ↓ ↑ ⊕ String and List Processing | ⊕ Horn clause | ⊕ Portugal | |
| Kanji PROLOG | ⊕ 1984 | ↓ ↑ ⊕ String and List Processing | ⊕ Horn clause | ⊕ Japan | |
| Prolog III | ⊕ 1984 | ↓ ↑ ⊕ String and List Processing | ⊕ Horn clause | ⊕ France | Prolog with unification replaced by constraint resolution. |
| Prolog/KR | ⊕ 1984 | ↓ ↑ ⊕ String and List Processing | ⊕ Horn clause | ⊕ Japan | Extension to prolog for Knowledge representation |