We give a general proof of Shahidi's tempered L-function conjecture, which
has previously been known in all but one case. One of the consequences is the
standard modules conjecture for p-adic groups, which means that the Langlands
quotient of a standard module is generic if and only if the standard module is
irreducible and the inducing data generic. We have also included the result
that every generic tempered representation of a p-adic group is a
sub-representation of a representation parabolically induced from a generic
supercuspidal representation with a non-negative real central character.