| CS-Prolog | ⊕ 1986 | ↓ ↑ ⊕ String and List Processing | ⊕ Horn clause | ⊕ Hungary | |
| ECRC-Prolog | ⊕ 1986 | ↓ ↑ ⊕ String and List Processing | ⊕ Horn clause | ⊕ United Kingdom | |
| Meta-Logic Prolog | ⊕ 1986 | ↓ ↑ ⊕ String and List Processing | ⊕ Horn clause | ⊕ Japan | |
| P-Prolog | ⊕ 1986 | ↓ ↑ ⊕ String and List Processing | ⊕ Horn clause | ⊕ Singapore | |
| Turbo Prolog | ⊕ 1986 | ↓ ↑ ⊕ String and List Processing | ⊕ Horn clause | ⊕ Denmark | |
| Waterloo Core Prolog | ⊕ 1986 | ↓ ↑ ⊕ String and List Processing | ⊕ Horn clause | ⊕ Canada |