  We present results for Kondo impurities in nanoscopic systems. Using exact
diagonalization in small clusters and Wilson's renormalization group we analyze
an isolated system and a nanoscopic system weakly coupled to a macroscopic
reservoir. In the latter case, new regimes not observed in macroscopic
homogeneous systems are induced by the confinement of conduction electrons.
These new confinement-induced regimes are very different depending on whether
the Fermi energy coincides with the energy of a resonant state or lies between
two quasi-bound states.
