  Two series of models were computed. The first series consists of 20 solar
mass models with varying initial metallicity (Z=0.02 down to Z=10^{-8}) and
rotation (V_{ini}=0-600 km/s). The second one consists of models with an
initial metallicity of Z=10^{-8}, masses between 9 and 85 solar masses and fast
initial rotation velocities (V_{ini}=600-800 km/s).
  The most interesting models are the models with Z=10^{-8} ([Fe/H]~-6.6). In
the course of helium burning, carbon and oxygen are mixed into the hydrogen
burning shell. This boosts the importance of the shell and causes a reduction
of the CO core mass. Later in the evolution, the hydrogen shell deepens and
produces large amount of primary nitrogen. For the most massive models (M>~60
solar masses), significant mass loss occurs during the red supergiant stage.
This mass loss is due to the surface enrichment in CNO elements via rotational
and convective mixing. The 85 solar mass model ends up as a WO type Wolf-Rayet
star. Therefore the models predict SNe of type Ic and possibly long and soft
GRBs at very low metallicities.
  The rotating 20 solar mass models can best reproduce the observed CNO
abundances at the surface of extremely metal poor (EMP) stars and the
metallicity trends when their angular momentum content is the same as at solar
metallicity (and therefore have an increasing surface velocity with decreasing
metallicity). The wind of the massive star models can also reproduce the CNO
abundances of the most metal-poor carbon-rich star known to date, HE1327-2326.
