The Continuum Shell Model is an old but recently revived method that traverses the boundary between nuclear many-body structure and nuclear reactions. The method is based on the non-Hermitian energy-dependent effective Hamiltonian. The formalism, interpretation of solutions and practical implementation of calculations are discussed in detail. The results of the traditional shell model are fully reproduced for bound states; resonance parameters and cross section calculations are presented for decaying states. Particular attention is given to one- and two-nucleon reaction channels including sequential and direct two-body decay modes. New calculations of reaction cross sections and comparisons with experimental data for helium and oxygen isotope chains are presented.

19 pages, 6 figures