  Continuum driving is an effective method to drive a strong stellar wind. It
is governed by two limits: the Eddington limit and the photon-tiring limit. A
star must exceed the effective Eddington limit for continuum driving to
overcome the stellar gravity. The photon-tiring limit places an upper limit on
the mass loss rate that can be driven to infinity, given the energy available
in the radiation field of the star. Since continuum driving does not require
the presence of metals in the stellar atmosphere it is particularly suited to
removing mass from low- and zero-metallicity stars and can play a crucial part
in their evolution. Using a porosity length formalism we compute numerical
simulations of super-Eddington, continuum driven winds to explore their
behaviour for stars both below and above the photon-tiring limit. We find that
below the photon tiring limit, continuum driving can produce a large, steady
mass loss rate at velocities on the order of the escape velocity. If the star
exceeds the photon-tiring limit, a steady solution is no longer possible. While
the effective mass loss rate is still very large, the wind velocity is much
smaller
