| ABCL/R3 | ⊕ 1998 | ↓ ↑ ⊕ Experimental and other | ⊕ Actor | ⊕ Japan | Concurrent object-oriented language |
| Alma-O | ⊕ 1998 | ↓ ↑ ⊕ Experimental and other | ⊕ Netherlands | Hybrid I/D language | |
| FORK | ⊕ 1998 | ↓ ↑ ⊕ Experimental and other | ⊕ Austria | PRAM-language | |
| LogTalk | ⊕ 1998 | ↓ ↑ ⊕ Experimental and other | ⊕ Portugal | OO Extensions to Prolog | |
| TAL | ⊕ 1998 | ↓ ↑ ⊕ Experimental and other | ⊕ Sweden | Temporal Action Logics |