  With more than 260 extrasolar planetary systems discovered to-date, the
search for habitable planets has found new grounds. Unlike our solar system,
the stars of many of these planets are hosts to eccentric or close-in giant
bodies. Several of these stars are also members of moderately close ($<$40 AU)
binary or multi-star systems. The formation of terrestrial objects in these
"extreme" environments is strongly affected by the dynamics of their giant
planets and/or their stellar companions. These objects have profound effects on
the chemical structure of the disk of planetesimals and the radial mixing of
these bodies in the terrestrial regions of their host stars. For many years, it
was believed that such effects would be so destructive that binary stars and
also systems with close-in giant planets would not be able to form and harbor
habitable bodies. Recent simulations have, however, proven otherwise. I will
review the results of the simulations of the formation and long-term stability
of Earth-like objects in the habitable zones of such "extreme" planetary
systems, and discuss the possibility of the formation of terrestrial planets,
with significant amounts of water, in systems with hot Jupiters, and also
around the primaries of moderately eccentric close binary stars.
