This package includes several classes that are common to the ACM package suite. Novice users of the package will, in general, not need to use most of these classes. The classes most likely to be of use are:

RandomGenerator

This class extends the Random class from java.util and offers a few useful simplifications for working with pseudorandom values.

MediaTools

This class includes several static methods that support the use of images and sounds.

ErrorException

This class is used to signal errors anywhere in the ACM Java Library collection. The primary advantage of ErrorException is that it is defined as a RuntimeException subclass and therefore does not need to be caught or declared in a throws clause.