High spin spectroscopy with emphasis on the study of superdeformed (SD) nuclei and the search for hyperdeformed nuclei. Determination of spins and excitation energies of SD bands by analysis of the quasi-continuum of gamm rays (continuum spectroscopy). Study of nuclei at very high spins and finite temperature using 2D gamma-gamma coincidences (ridge spectroscopy) using the Gammasphere -and GRETA spectrometers coupled to the FMA and AGFA mass spectrometers. Monte Carlo model simulations of the feeding of normal and SD states as well as the decay of SD bands. Development of gamma-ray tracking algorithms for the new generation gamma--ray detector GRETINA, a novel array of highly segmented germanium detectors using digital electronics and pulse shape analysis. Development of new software analysis packages, both for on--line and off--line use, of data from GRETA and digital GAMMASPHERE coupled to ancillary detectors. Monte Carlo simulations using the GEANT4 package from CERN to ascertain the tracking performance of GRETA and AGATA. Measurements of angular distributions and correlations as well as linear polarization of gamma rays measured in tracking arrays.