  We discuss recent models on the evolution of massive stars at very low
metallicity including the effects of rotation, magnetic fields and binarity.
Very metal poor stars lose very little mass and angular momentum during the
main sequence evolution, and rotation plays a dominant role in their evolution.
In rapidly rotating massive stars, the rotationally induced mixing time scale
can be even shorter than the nuclear time scale throughout the main sequence.
The consequent quasi-chemically homogeneous evolution greatly differs from the
standard massive star evolution that leads to formation of red giants with
strong chemical stratification. Interesting outcomes of such a new mode of
evolution include the formation of rapidly rotating massive Wolf-Rayet stars
that emit large amounts of ionizing photons, the formation of a long gamma-ray
bursts and a hypernovae, and the production of large amounts of primary
nitrogen. We show that binary interactions can further enhance the effects of
rotation, as mass accretion in a close binary spins up the secondary.
