This paper reviews the 25-plus year history of significant developments of the GENESIS shoreline response model. Topics discussed are line sources and sinks of sand, representation of shore-normal structures including natural sand bypassing, wave transmission by and shoreline response to shore-parallel structures, seawalls, migrating longshore sand waves, seasonal variation by cross-shore sand transport, sand transport due to tidal and wind-generated currents, preservation of the regional shape of the shoreline, and the interaction between the beach berm and the dunes behind it. Such developments have been done in a consistent way, based on thorough literature reviews, beta testing, comparison to beach behavior, and quality control. The challenges have been not only to represent the features themselves, but to be consistent to the basic assumptions of shoreline modeling theory. Through these added capabilities, GENESIS has evolved to meet the challenges of modern, multi-scale, long-term coastal engineering applications.