Despite the long history of research on the theoretical and practical generation of chemical graphs, the number of publicly available algorithms and software for this purpose is still limited. For several decades, the closed-source, commercial structure generator MOLGEN, developed at the University of Bayreuth, marks the state of the art in terms of speed and completeness. Recognising the need for an open-source structure generator, Peironcely et al. developed the Open Molecule Generator (OMG). OMG, however, is orders of magnitude slower than MOLGEN. The 452,458 isomers of C 10 H 16 O, for instance, are generated in only 5 seconds by MOLGEN, whereas OMG takes 22 minutes on the same machine (a 2020 Macbook Pro, 2,3 GHz 8-Core Intel Core i9). For more benchmarks, please see the results section of the present manuscript.