  We review recent work on the holographic duals of type II and heterotic
matrix string theories described by warped AdS_3 supergravities. In particular,
we compute the spectra of Kaluza-Klein primaries for type I, II supergravities
on warped AdS_3xS^7 and match them with the primary operators in the dual
two-dimensional gauge theories. The presence of non-trivial warp factors and
dilaton profiles requires a modification of the familiar dictionary between
masses and ``scaling'' dimensions of fields and operators. We present these
modifications for the general case of domain wall/QFT correspondences between
supergravities on warped AdS_{d+1}xS^q geometries and super Yang-Mills theories
with 16 supercharges.
