  The Global Colour Model (GCM) of QCD is a very successful model. Not only is
it formally derivable from QCD but under various conditions it reduces to the
NJL model and also to Chiral Perturbation Theory, and to other models. Results
presented include the effective gluon propagator, the difference between
constituent and exact quark propagators, various meson and nucleon observables,
a new mass formula for the Nambu-Goldstone mesons of QCD, and the change in the
MIT bag constant in nuclei.
