Chemical structure generators enumerate or generate molecular graphs of organic or bioorganic molecules. They are an integral part of systems for computer-assisted structure elucidation (CASE) and can be used to create molecular libraries for virtual screening , or enumerate chemical spaces in general . The history of chemical graph generators goes back at least to the 1960s DENDRAL project which was aimed at the CASE of organic molecules based on mass spectrometric data . DENDRAL was developed for NASA's Mariner program to search for life on Mars . Its structure generator used substructures as building blocks and was able to deal with overlapping substructures. In the early history of the structure generators, ASSEMBLE was another building block based structure generator . In the field, there is a family of generators based on mathematical theorems such as algorithmic group theory and combinatorics . Besides DENDRAL, MASS was also another good example for the applications of mathematical theorems in structure generation. It was a tool for the mathematical analysis of molecular structures. SMOG was the successor of the MASS algorithm. Many works followed but few examples of practical usability are available even today . Among the currently available structure generators, such as DENDRAL, ASSEMBLE, SMOG, COCON and LSD , MOLGEN constituted the state-of-the-art for decades in terms of speed, completeness and reliability. The first version of MOLGEN was based on the strategy of DENDRAL software and developed to overcome the limitations of DENDRAL . The software is based on the orderly graph generation method . Although MOLGEN is the de facto gold standard in the field, it has the downside of being closed-source software. The algorithm cannot be further developed or modified by scientists based on their interests. The most efficient and fast open-source chemical graph generator was MAYGEN based on the orderly generation method. However, MAYGEN is approximately 3 times slower than MOLGEN. The state of the art of large scale structure generation was recently set by the lab of Jean-Louis Reymond in developing an in-house solution for a nauty-based structure generator, which enabled them to produce the numeration of 166 billion organic small molecules in the chemical universe database GDB-17. To the best of our knowledge, this in-house generator was not released as open-source or otherwise. Thus, there is still the need for an efficient open-source chemical graph generator. In we expressed the hope to "trigger a surge in the development of improved and faster" structure generators. Here we present the novel structure generator surge, based on the principle of the canonical generation path method. Surge is open-source and outperforms MOLGEN 5.0 by orders of magnitude in speed. Furthermore, surge is easily extensible with more features and adaptable to further application.