The Digital Shoreline Analysis System (DSAS) is a freely available software application that works within the Environmental Systems Research Institute (ESRI) Geographic Information System (ArcGIS) software. DSAS computes rate-of-change statistics for a time series of shoreline vector data. Additionally, the DSAS application is useful for computing rates of change for any boundary-change problem that incorporates a clearly-identified feature position at discrete times, such as glacier limits, river banks, or land use/cover boundaries. The "bias feature" is a shapefile representation the proxy-datum bias (PDB) data previously published in tabular format (Himmelstoss and others 2010, Himmelstoss and others 2018). These PDB data are used to shift older proxy-based shorelines so that they can be directly compared to newer datum-based shorelines and accurate rates can be calculated.