This review discusses first our present microscopic understanding of t
he neutral quantum liquids He-4 and He-3. Quantum liquids in non-unifo
rm geometries such as adsorbed or free films and clusters lead, due to
symmetry breaking, to a number of new and interesting effects and, th
us, to new experimental possibilities and theoretical challenges. Fina
lly, we highlight some open problems where new microscopic techniques
will be needed.