The Expere Document Engine uses the Apache logging project’s Log4j. Log4j is a flexible and configurable logging system. By default, the Expere Document Engine is configured to send log messages of priority FATAL to the standard output stream. The Log4j configuration is defined in the log4j.xml file in the Expere Document Engine EAR. The configuration of Log4j is documented at the Log4j project home at http://logging.apache.org/log4j/docs/index.html. Consult the documentation for detailed information about the configuration of Log4j.