  We review a model--based rather than phenomenological approach to
low--temperature anomalies in glasses. Specifically, we present a solvable
model inspired by spin--glass theory that exhibits both, a glassy
low--temperature phase, and a collection of double-- and single--well
configurations in its potential energy landscape. The distribution of
parameters characterizing the local potential energy configurations can be
computed, and is found to differ from those assumed in the standard tunneling
model and its variants. Still, low temperature anomalies characteristic of
amorphous materials are reproduced. More importantly perhaps, we obtain a clue
to the universality issue. That is, we are able to distinguish between
properties which can be expected to be universal and those which cannot. Our
theory also predicts the existence, under suitable circumstances of amorphous
phases without low--energy tunneling excitations.
