Multi-functional Calculation Program for Nuclear Design and Safety Evaluation (TopMC, updated and extended version of SuperMC) is a large-scale nuclear design software, which has been developed by FDS Consortium for more than 20 years. Taking radiation transport calculation as the core, TopMC supports the whole process neutronics calculation containing depletion, radiation source term/dose/biohazard, material activation and transmutation. It is featured with high efficiency and high fidelity multi-physics calculation, accurate modeling, visualized intelligent analysis and virtual simulation. As the extended versions of TopMC, neutron detection software, neutron logging software, neutron therapy software, and so on have been developed. TopMC can be used for the design and safety evaluation of nuclear energy systems, as well as nuclear technology application fields including radiation medicine, nuclear detection and so on.