| ALGOL 68 | 1968 | Numerical Scientific | True ALGOL68s | International | 3rd generation ALGOL |
| ALGOL 68 Revised | 1975 | Numerical Scientific | True ALGOL68s | International | |
| Algol 68 with areas | 1972 | Experimental and other | True ALGOL68s | United Kingdom | Addition of areas to Algol 68 |
| ALGOL 68+ | 1980 | Numerical Scientific | True ALGOL68s | Netherlands | Superlanguage of ALGOL 68 |
| ALGOL 68C | 1975 | Numerical Scientific | True ALGOL68s | United Kingdom | Cambridge Algol 68 |
| Algol 68G | 0 | ||||
| ALGOL 68-R | 1970 | Numerical Scientific | True ALGOL68s | United Kingdom | |
| ALGOL 68RS | 1972 | Numerical Scientific | True ALGOL68s | United Kingdom | Extended RS Algol |
| ALGOL 68-RT | 1979 | Numerical Scientific | True ALGOL68s | United Kingdom | Parallel ALGOL 68-R |
| ALGOL 68S | 1977 | Numerical Scientific | True ALGOL68s | International | Simplified version of ALGOL 68 |