  We develop some aspects of the theory of derivators, pointed derivators, and
stable derivators. As a main result, we show that the values of a stable
derivator can be canonically endowed with the structure of a triangulated
category. Moreover, the functors belonging to the stable derivator can be
turned into exact functors with respect to these triangulated structures. Along
the way, we give a simplification of the axioms of a pointed derivator and a
reformulation of the base change axiom in terms of Grothendieck (op)fibration.
Furthermore, we have a new proof that a combinatorial model category has an
underlying derivator.
