  Grids of models for rotating stars are constructed in the range of 9 to 120
M$_{\odot}$ at solar metallicity. The following effects of rotation are
included: shellular rotation, new structure equations for non-conservative
case, surface distorsions, increase of mass loss with rotation, meridional
circulation and interaction with horizontal turbulence, shear instability and
coupling with thermal effects, advection and diffusion of angular momentum
treated in the non-stationary regime, transport and diffusion of the chemical
elements.
  Globally we find that for massive stars the effects of rotation have an
importance comparable to those of mass loss. For an average rotation, the
tracks in the HR diagram are modified like a moderate overshoot would do. In
general, an average rotation may increase the MS lifetime up to about 30 %; for
the helium-burning phase the effects are smaller and amount to at most 10 %.
  Rotation also brings significant surface He- and N-enhancements, they are
higher for higher masses and rotation.
