[en] The structure and capabilities of the set of programs for simulating the neutron-physical experiments by the Monte Carlo method are described. Geometric modUles, evaluation moduless source simulating are considered. Combining different modules one can simulate experiments on measurement of integral and differential transmission function, measurement of cross sections of different processes by means of activation as well as time-of-flight methods. There appears the possibility to estimate multiple scattering effects, different containers and other equipment contribution to find detector response functions etc. The complex structure is open and continuously filled up. The constant system employed is oriented to the detailed account of processes of neutron and gamma-quanta interaction with the matter. The set of programs is composed according to the module principle and realized at the BESM-6 computer