Earthquake seismology, like most areas of geophysics, is a fascinating mix of theory, computation, and observation. The past 50–60 years of earthquake seismology can be described as a synergistic interaction between the expanding quantity and improving quality of seismic data and important advances in practical wave-propagation physics and computation. An important impetus for many of these developments was the need to monitor and characterize nuclear explosions in the atmosphere, oceans, and underground, which stimulated a major investment in seismology during the 1960s that, combined with the plate tectonics revolution, initiated large growth in the field. Substantial effort was invested to produce standard analysis packages and software tools for the processing and analysis of seismic observations. As a result, high-quality seismic data are readily accessible and sufficient computational power to routinely analyze these observations is available to almost everyone. Turn-key seismic networks are available from manufacturers who provide sensors, data acquisition and transmission, event location, and archival functions in a manner that requires training, but not a detailed understanding of the of the hardware or software packages. As we advance toward more sophisticated analysis of everlarger data sets, including the effects of 3D structure, the practical and theoretical challenges facing students are substantial. Students must adapt to research-quality software and use it to develop the deep insight into seismic-wave excitation and propagation before they can confidently apply the concepts to more sophisticated earth and earthquake models. Although beginning students have the skills to use some tools such as word processors and have some scripting experience, many are less comfortable extending old or developing new analysis tools or even using existing codes to tackle realistic 1D problems. The challenge facing educators is to enable students to quickly become proficient in basic seismic data processing so that they can move on to research that is more meaningful. The Computer Programs in Seismology (CPS) package provides a set of tools and includes a number of tutorials that may help the young researchers develop essential skills needed for the study of the Earth and seismic sources.

The purpose of this article is to review the history of the package, to show how it can be used, and to highlight a few of the programs that are heavily used in data analysis. The history of the software development is one that has probably been repeated in most larger research groups, and we review it partially to provide some context for the younger readers, who work in a very different computational environment than existed even ten years ago.