Rustics implements a simple set of statistics objects intended primarly for measuring performance parameters. It provides statistics objects that collected data and compute various statistical characterizations of the data, such as the mean and variance.

This library also implements sets, which contain statistics that are printed and manipulated together. Sets are recursive: a set can have a set as a member. A set hierarchy can be printed with a single procedure call, and the contained statistics object can be cleared in the same way. The set implementation automatically creates hierarchical names for objects. Each set or statistic typically will have a single element name, and the period (".") will be used to create a hierchical name in the manner of a Unix filesystem.

Statistics and sets can be deleted, but the code uses simple algorithms that are linear in the number of elements of a set to do searching for items to be deleted, so sets with a very high number of subsets or statistics can require a long time to process a deletion.