Hi: I run the NewRuleCalculator.java to learn Joran feature - interpreter to learn new rules on the fly. I modified line of 57 as simpleConfigurator.doConfigure("src/main/java/chapters/onJoran/newRule/newRule.xml"); first of all, newRule.xml has typo for xml element "new-rule" , it should be "newRule" after correcting above error, the NewRuleCalculator.java run fine but didn't generate expected result as "The computation named [toto] resulted in the value 30" See below output from my IDE: cd D:\OpenSourceCodes\logback-master\logback-examples; JAVA_HOME=D:\\Java\\jdk1.7.0_15 "\"D:\\Program Files\\NetBeans 7.3\\java\\maven\\bin\\mvn.bat\"" "-Dexec.args=-classpath %classpath chapters.onJoran.newRule.NewRuleCalculator" -Dexec.executable=D:\\Java\\jdk1.7.0_15\\bin\\java.exe -Dexec.classpathScope=runtime -DskipTests=true process-classes org.codehaus.mojo:exec-maven-plugin:1.2.1:execScanning for projects... ------------------------------------------------------------------------Building Logback Examples Module 1.0.12-SNAPSHOT------------------------------------------------------------------------ [build-helper:add-test-source]Test Source directory: D:\OpenSourceCodes\logback-master\logback-examples\src\test\scala added. [resources:resources][debug] execute contextualizeUsing 'UTF-8' encoding to copy filtered resources.Copying 3 resources [compiler:compile]Compiling 1 source file to D:\OpenSourceCodes\logback-master\logback-examples\target\classes [exec:exec]------------------------------------------------------------------------BUILD SUCCESS------------------------------------------------------------------------Total time: 1.532sFinished at: Sun Mar 31 16:53:19 PDT 2013Final Memory: 9M/24M------------------------------------------------------------------------ Source code : downloading logback-master.zip from https://github.com/qos-ch/logbackIDE: NetBeans 7.3JDK version: 32 bit window version Oracle JDK 1.7.0_15Platform: window xp Ming Qin Cell Phone Number: 949-388-9898