Despite years of computing progress, today's systems experience spectacular and all-too-frequent crashes, while many enormously expensive projects fail to produce anything useful. Of equal importance, and potentially more damaging, are the misleading smaller defects we tend to miss. From time to time, we must remind ourselves that the underlying quality of the software that our results and progress increasingly depend on will likely be flawed and even more dependent on independent corroboration than the science itself. Many scientific results are corrupted, perhaps fatally so, by undiscovered mistakes in the software used to calculate and present those results.