This package provides comprehensive implementations of the rough set theory (RST) and the fuzzy rough set theory (FRST), and integrates these two theories into a single package. It provides implementations, not only for the basic concepts of RST and FRST, but also most common methods based on them for handling some tasks such as discretization, feature selection, instance selection, rule induction, and prediction. RST was introduced by Zdzislaw Pawlak in 1982 as a sophisticated mathematical tool based on indiscernibility relations to model and process imprecise or incomplete information. It works on symbolic-valued datasets for tackling the data analysis problems. By using the indiscernibility relation for objects/instances, RST does not require additional parameters to analyze the data. FRST is an extension of RST. The FRST combines concepts of vagueness and indiscernibility that are expressed with fuzzy sets (as proposed by Zadeh, in 1965) and RST.