||Every software developer, from the individual amateur to the largest enterprise, dreams of giving rise to a “killer application (commonly shortened to killer app) that is so useful or desirable that it proves the value of some under-lying technology”1. Whether the ‘killer app’ provides financial benefits either to the developer or the hardware platform vendor is beside the point. The important thing is the professional or social component: a true ‘killer app’ radically alters some form of human activity, either by creating an activity that did not exist before, or by im-proving the performance of an activity so dramatically that its practitioners view it as a revolutionary change. The first set of ‘killer apps’ so named, the early spread-sheet programs VisiCalc and Lotus 1-2-3, certainly revo-lutionized finance, accounting, engineering and many other professional disciplines. These programs, in fact, engendered the pursuit of the dream referred to above. The title of the talk is not “How to create a killer app in Civil Engineering” but “What makes and doesn't make a killer app in Civil Engineering.” Forecasting is always a tough art. Given the wide range of human activities, it is even tougher to predict what tool will radically alter one such activity. Retrospective appraisal is much easier: you just need to evaluate what happened and attempt to trace from causes to consequences. Furthermore, because of the rarity of ‘killer apps’ generally, and in civil engineering particularly, it is not possible to treat the subject in any generic way; it can only be treated by evaluating exam-ples and attempting to generalize from them.