Despite widespread use of radio-echo sounding (RES) in glaciology and broad distribution of processed radar products, the glaciological community has no standard software for processing impulse RES data. Dependable, fast, and collection-system/platform independent processing flows could facilitate comparison between datasets and allow full utilization of new data. Here, we present ImpDAR, an open-source, cross-platform, impulse radar processor and interpreter, written primarily in Python. While processing techniques are well established, the utility of this software is its collection of established tools, into a single, open-source framework. ImpDAR aims to provide a versatile standard that is accessible to radar-processing novices and useful to radar specialists. It can read data from common commercial ground-penetrating radars (GPRs) and some custom-built RES systems. It performs all the standard processing steps, including bandpass and horizontal filtering, time correction for antenna spacing, geolocation, and migration. After processing data, ImpDAR’s interpreter enables several plotting functions, digitization of reflecting horizons, calculation of reflector strength, and export of interpreted layers. We demonstrate these capabilities on two datasets: deep (~3000-m depth) data collected with a custom (3 MHz) system in northeast Greenland and shallow (< 100-m depth, 500 MHz) data collected with a commercial GPR on South Cascade Glacier in Washington.