  Several concepts have been brought forward to determine where terrestrial
planets are likely to remain habitable in multi-stellar environments.
Isophote-based habitable zones, for instance, rely on insolation geometry to
predict habitability, whereas radiative habitable zones take the orbital motion
of a potentially habitable planet into account. Dynamically informed habitable
zones include gravitational perturbations on planetary orbits, and full scale,
self consistent simulations promise detailed insights into the evolution of
select terrestrial worlds. All of the above approaches agree that stellar
multiplicity does not preclude habitability. Predictions on where to look for
habitable worlds in such environments can differ between concepts. The aim of
this article is to provide an overview of current approaches and present simple
analytic estimates for the various types of habitable zones in binary star
systems.
