| ASKCOS | The most comprehensive (feature-wise) open-source suite for multistep planning from MIT. | 1 version |
| AiZynthFinder | A robust, well-maintained implementation of the MCTS and Retro* algorithms from AstraZeneca. | 4 versions |
| DirectMultiStep | An approach reformulating multistep retrosynthetic planning as a sequence translation task, bypassing explicit iterative search. Developed at Yale. | 1 version |
| Retro* | Original implementation of Retro* from the original paper by Georgia Tech. | 2 versions |
| SynPlanner | A flexible implementation of MCTS with CGRTools under the hood. Developed at University of Strasbourg | 5 versions |
| Syntheseus | A standardized and flexible Retro* harness for different single-step predictors developed by Microsoft | 1 version |