We compared six sound analysis/synthesis systems used for computer music. Each system analysed the same collection of twenty-seven varied input sounds, and output the results in Sound Description Interchange Format (SDIF). We describe each system individually then compare the systems in terms of availability, the sound model(s) they use, interpolation models, noise modelling, the mutability of various sound models, the parameters that must be set to perform analysis, and characteristic artefacts. Although we have not directly compared the analysis results among the different systems, our work has made such a comparison possible.