| Occam | 1982 | Multi-purpose | Pascals | United Kingdom | Parallel Wirth Algol for Transputers |
| Occam 2 | 1987 | United Kingdom | Improved version of Occam | ||
| Occam 2.1 | 1990 | Multi-purpose | United Kingdom | Improved Occam 2 | |
| Occam 3 | 1992 | United Kingdom | |||
| occam-T | 1987 | Australia | tasmanian safe occam dialect |