  We use generalized unitarity at the integrand-level to directly construct
local, manifestly dual-conformally invariant formulae for all two-loop
scattering amplitudes in planar, maximally supersymmetric Yang-Mills theory
(SYM). This representation separates contributions into manifestly finite and
divergent terms---in a way that makes manifest the exponentiation of infrared
divergences at the integrand-level. These results perfectly match the all-loop
BCFW recursion relations, to which we provide a closed-form solution valid
through two-loop-order. Finally, we describe and document a Mathematica package
which implements these results, available as part of this work's source files
on the arXiv.
