  Due to the peculiar non-fermi liquid of one dimensional systems, disorder has
particularly strong effects. We show that such systems belong to the more
general class of disordered quantum solids. We discuss the physics of such
disordered interacting systems and the methods that allows to treat them. In
addition to, by now standard renormalization group methods, We explain how a
simple variational approach allows to treat these problems even in case when
the RG fails. We discuss various physical realizations of such disordered
quantum solids both in one and higher dimensions (Wigner crystal, Bose glass).
We investigate in details the interesting example of a disordered Mott
insulator and argue that intermediate disorder can lead to a novel phase, the
Mott glass, intermediate between a Mott and and Anderson insulator.
