1.0 1.1 log http://jakarta.apache.org/taglibs/log-1.0 The Log library allows you to embed logging calls in your JSP which can be output to a variety of destinations thanks to the power of the log4j project. Initialising log4jBy default these log tags do not explicitly initialise log4j, you are free to do that however you wish. A common approach is to create a log4j servlet and for it to initialise log4j using some configuration file or options specified in your web.xml My own personal preference is just to put a log4j.properties file in the WEB-INF/classes directory and for that to have your log4j configuration. Then without any special servlets or initialisation code log4j will correctly initialise itself. This approach also avoids a single web app accidentally initialising log4j several times (e.g. via 2 different servlets). If you have any further questions regarding the configuration of log4j please visit the log4j site or a log4j specific mailing list. debug org.apache.taglibs.log.DebugTag category false true message false true info org.apache.taglibs.log.InfoTag category false true message false true warn org.apache.taglibs.log.WarnTag category false true message false true error org.apache.taglibs.log.ErrorTag category false true message false true fatal org.apache.taglibs.log.FatalTag category false true message false true dump org.apache.taglibs.log.DumpTag scope true true