The doc for com.sun.tools.attach.VirtualMachine.loadAgentPath(String agentPath) (http://java.sun.com/javase/6/docs/jdk/api/attach/spec/index.html) says that 'agent library provided is the absolute path from which to load the agent library', actually it also accepts non-absolute paths. For example on linux if pass to loadAgentPath platform specific expanded library name (e.g. libagent.so) and LD_LIBRARY_PATH contains path to the library it will be successfully loaded.