Utility classes useful for the implementation of other packages, but not necessarily part of any one package. Also, ideally no class in util creates a dependence on another package. A good rule of thumb is that classes that are useful to more than one package that do not depend on any of those packages should go here.

For example, here are some examples of classes in the package: TimeParser, a generally useful class for parsing formatted time strings. Another is Crypt, a class for encrypting passwords with the crypt algorith. Probe breaks the stated rules, because it utilizes the package graph to plot data. It should find a new home.