| ART | ⊕ 1984 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | Automated Reasoning Tool |
| ART-IM | ⊕ 1990 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | ART with CLIPS features |
| C5 | ⊕ 1988 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | C based version of OPS-5 |
| CLIPS | ⊕ 1986 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | C Language Integrated Production System |
| CLIPS/R2 | ⊕ 1990 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | Rete/2 CLIPS |
| Clips++ | ⊕ 1996 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | rewrite with extension of CLIPS in C++ |
| Eclipse | ⊕ 1989 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | Extended CLIPS |
| FZCLIPS | ⊕ 1995 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ Canada | Fuzzy extensions to CLIPS |
| GPS | ⊕ 1957 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | General Problem Solver |
| JESS | ⊕ 1995 | ↓ ↑ ⊕ Specialised Languages | RETE and production | Java Expert System Shell | |
| LISA | ⊕ 2000 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | LISP expert system shell |
| MAGSY | ⊕ 1985 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ Germany | Multi-agent OPS5 |
| OPS | ⊕ 1970 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | Official Production System |
| OPS/R2 | ⊕ 1985 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | Production system |
| OPS2 | ⊕ 1978 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | Official Production System version 2 |
| OPS3 | ⊕ 1979 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | Official Production System version 3 |
| OPS4 | ⊕ 1979 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | Official Production System version 4 |
| OPS5 | ⊕ 1979 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | Official Production System version 5 |
| OPS5+ | ⊕ 1983 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | PC version of OPS5 |
| OPS6 | ⊕ 1981 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | Production system |
| OPS7 | ⊕ 1983 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | Production system |
| OPS83 | ⊕ 1983 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | Official Production System 1983 version |
| OPSAda3 | ⊕ 1984 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | |
| OPSJ | ⊕ 1988 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | Production system |
| Oramant Problem Solver | ⊕ 1969 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ India | |
| PCLIPS | ⊕ 1990 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | Parallel CLIPS |
| PSG | ⊕ 1969 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ United States | |
| RDL/C | ⊕ 1990 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ France | |
| RDL1 | ⊕ 1988 | ↓ ↑ ⊕ Specialised Languages | RETE and production | ⊕ France | |
| RPL | ⊕ 1988 | ↓ ↑ ⊕ Business Data Processing | RETE and production | ⊕ United States | The Relational Production Language |