Wilson\'s numerical renormalization group.- The Density Matrix Renormalization Group.- Thermodynamic limit and matrix-product states.- A recurrent variational approach.- Transfer-matrix approach to classical systems.- Quantum transfer-matrix and momentum-space DMRG.- Calculation of dynamical properties.- Properties of the hubbard chain.- Soliton bound-states in dimerized spin chains.- Haldane phase, impurity effects and spin ladders.- Spin chain properties.- Electronic structure using DMRG.- Symmetrized DMRG method for conjugated polymers.- Conjugated one-dimensional semiconductors.- Strongly correlated complex systems.- Non-hermitian problems and some other aspects.- Walls, wetting and surface criticality.- Critical two-dimensional ising films with fields.- One-dimensional Kondo lattices.- Impurities in spin chains.- Thermodynamics of ferrimagnets.- Thermodynamics of metallic kondo lattices.- Methods for electron-phonon systems.- Disordered one-dimensional fermi systems.