Both kie-api.jar and drools-compiler.jar contain org/kie/KieBase.class ---------------------------------------------------------------------- Key: DROOLS-52 URL: https://issues.jboss.org/browse/DROOLS-52 Project: Drools Issue Type: Bug Security Level: Public(Everyone can see) Reporter: Geoffrey De Smet Assignee: Geoffrey De Smet Priority: Blocker Both kie-api.jar and drools-compiler.jar contain org/kie/KieBase.class. It looks like drools-compiler is fat jar. Fat jars (even shaded fat jars) are evil. See slide 39-42: http://ge0ffrey.github.com/maven-dependency-puzzlers/maven-dependency-puz... Certain platforms (android, ...) don't even allow to deploy such jars. Others (osgi, ...) throw warnings.