NagiosAppender is a pure Java implementation of a Log4j appender that allows the developer/administrator to send log records to Nagios via the NCSA server (using the push model). It provides a simple solution for Nagios administrators whose only alternative is to implement a polling function against against the output of a standard Log4j appender. The log4j configuration file provides for user-specific mappings between Log4j levels and Nagios levels. The configuration file also allows the user to select whether to set the Nagios 'service' and 'host' programmatically via Log4j MDC, or via the config file. Later releases support XOR encryption.