  I briefly review some general features and some recent developments
concerning the resummation of long-distance singularities in QCD and in more
general non-abelian gauge theories. I emphasize the field-theoretical tools of
the trade, and focus mostly on the exponentiation of infrared and collinear
divergences in amplitudes, which underlies the resummation of large logarithms
in the corresponding cross sections. I then describe some recent results
concerning the conformal limit, notably the case of N = 4 superymmetric
Yang-Mills theory
