Reproducibility is emerging as a major issue for highly parallel computing, in much the same way (and for many of the same reasons) that it is emerging as an issue in other fields of science, technology and medicine, namely the growing numbers of cases where other researchers cannot reproduce published results. This talk will summarize a number of these issues, including the need to carefully document computational experiments, the growing concern over numerical reproducibility and, once again, the need for responsible reporting of performance. Have we learned the lessons of history?