  We calculate the complete quark and gluon cusp anomalous dimensions in
four-loop massless QCD analytically from first principles. In addition, we
determine the complete matter dependence of the quark and gluon collinear
anomalous dimensions. Our approach is to Laurent expand four-loop quark and
gluon form factors in the parameter of dimensional regularization. We employ
finite field and syzygy techniques to reduce the relevant Feynman integrals to
a basis of finite integrals, and subsequently evaluate the basis integrals
directly from their standard parametric representations.
