Hello, Logback is a rewrite of log4j based on the lessons learned during the years. Logback has a smaller memory footprint and is faster by a wide margin. It has much better error reporting capability and is generally more robust. Logback has support for markers which enables capabilities not found elsewhere. We will be documenting these capabilities in the near future. Just as imporantly, logback`s access module supports Tomcat and Jetty. Thus, many of the logging capabilites offered by the classic module are also available for http access logging. I hope this anwers your question, -- -- Ceki Gülcü For log4j documentation consider "The complete log4j manual" http://www.qos.ch/shop/products/eclm/