  I discuss the state-of-the-art knowledge of long-distance singularities in
multi-leg gauge-theory scattering amplitudes and report on an on-going
calculation of the three-loop soft anomalous dimension through the
renormalization of correlators of semi-infinite Wilson lines. I also discuss
the non-Abelian exponentiation theorem that has been recently generalised to
multiple Wilson lines and demonstrate its application in computing the soft
anomalous dimension. Finally, I present recent results for
multiple-gluon-exchange webs and discuss their analytic structure.
