  Taking advantage of the quantale-theoretic description of \'etale groupoids
we study principal bundles, Hilsum-Skandalis maps, and Morita equivalence in
terms of modules on inverse quantal frames. The Hilbert module description of
quantale sheaves leads naturally to a formulation of Morita equivalence in
terms of bimodules that resemble imprimitivity bimodules of C*-algebras.
