  The feedback effects of massive stars on their galactic and intergalactic
environments can dominate evolutionary processes in galaxies and affect cosmic
structure in the Universe. Only the Local Group offers the spatial resolution
to quantitatively study feedback processes on a variety of scales. Lyman
continuum radiation from hot, luminous stars ionizes HII regions and is
believed to dominate production of the warm component of the interstellar
medium (ISM). Some of this radiation apparently escapes from galaxies into the
intergalactic environment. Supernovae and strong stellar winds generate shell
structures such as supernova remnants, stellar wind bubbles, and superbubbles
around OB associations. Hot (10^6 K) gas is generated within these shells, and
is believed to be the origin of the hot component of the ISM. Superbubble
activity thus is likely to dominate the ISM structure, kinematics, and phase
balance in star-forming galaxies. Galactic superwinds in starburst galaxies
enable the escape of mass, ionizing radiation, and heavy elements. Although
many important issues remain to be resolved, there is little doubt that
feedback processes plays a fundamental role in energy cycles on scales ranging
from individual stars to cosmic structure. This contribution reviews studies of
radiative and mechanical feedback in the Local Group.
