  We present on the use of on-shell recursion relations. These can be used not
only for calculating tree amplitudes, including those with masses, but also to
compute analytically the missing rational terms of one-loop QCD amplitudes.
Combined with the cut-containing pieces calculated using a unitarity approach
complete one-loop QCD amplitudes can be derived. This approach is discussed in
the context of the adjacent 2-minus all-multiplicity QCD gluon amplitude.
