This talk by Ceki GÃ¼lcÃ¼ at Jazoon 2009 presents the SLF4J and logback projects. SLF4J is a logging abstraction gaining wide acceptance in the Java community. Logback is the successor of the log4j project. The logging abstraction problem is presented. SLF4J tackles this problem in a decidedly unsophisticated manner. There are significant lessons to be learned from SLF4J’s approach. Logback, as the successor to log4j, is an evolution of the former project. It builds on the log4j experience, first by modularizing according to intended usage and second by simplifying the implementation. As a result, logback accomplishes more with less code. In addition to lessons learned and design principles, the talk is accompanied by several examples.