Two environment variables have to be initialized before ABACUS can be used. The environment variable ABACUS_LICENSE_DIR receives the name of the directory in which the file .abacusLicense is stored. The environment variable ABACUS_DIR is initialized with the directory containing the general configuration file .abacus. A master version of this configuration file is available in the abacus package. However, every user might want to make his modifications. Therefore, it is recommendable that every user makes a private copy of the file .abacus.