Info message when starting with Tomcat 5.5 indicates that using a natively compiled APR library instead of the generic one may result in performance increase. It looks worth checking out in case it is useful to recommend to Tomcat Apache users or even bundle in platform-specific Standalones.

Message - "INFO: The Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: (path here)"

APR library link is http://tomcat.apache.org/tomcat-5.5-doc/apr.html