SUSY GUT model building

The evolution of SUSY GUT model building is discussed, starting with the construction of 4D GUTs, to orbifold GUTs and finally to orbifold GUTs, within the heterotic string model. This evolution is an attempt to obtain realistic string models, perhaps relevant for the LHC. This review is in memory of the sudden loss of Julius Wess, a leader in the field, who will be sorely missed.