Screenshots of the cross-platform PRIMUS. (a) One experimental profile with errors is displayed. The `Documents' panel may be undocked and moved freely. It may hold a (virtually) unlimited number of files, provides access to the most frequently used operations and keeps a list of recently used files. (b) Interactive estimation of the radius of gyration. Advanced options are hidden by default; the display of residuals may be enabled or disabled. Zooming, panning and export to various graphics formats are available. (c) Estimation of the distance distribution; the fit to the data and the P(r) function are shown next to each other and instantly updated if any of the configuration options is changed. Advanced options are hidden by default.