  I review progress made in solving gauge theories such as collinear quantum
chromodynamics using light-cone Hamiltonian methods. I also show how the
light-cone Fock expansion for hadron wavefunctions can be used to compute
operator matrix elements such as decay amplitudes, form factors, distribution
amplitudes, and structure functions, and how it provides a tool for exploring
novel features of QCD. I also review commensurate scale relations,
leading-twist identities which relate physical observables to each other, thus
eliminating renormalization scale and scheme ambiguities in perturbative QCD
predictions.
