Hi, Here's some suggestions for troubleshooting the install. The CLASSPATH needs to be $SJAVA_HOME/org/omegahat/Jars/Environment.jar, $SJAVA_HOME/org/omegahat/Jars/antlr.jar $SJAVA_HOME/org/omegahat/Jars/jas.jar $SJAVA_HOME. This allows the java compiler/interpreter to find 1)the ROmegahatInterpreter and REvaluator classes(in a org/omegahat/R/Java tree under SJava 2)& the base omegahat interpreter libraries from which the ROmegahatInterpreter & REvaluator classes descend.(Found in those jar files) on Unix-like systems, the LD_LIBRARY_PATH has to point to the shared objects(so)/dynamic linking libraries, usually in $R_HOME/libs. These .so/.dll files have to be symbolically linked to other names. This is because the Java/JNI loader needs a specific naming convention to load symbol libraries/shared objects(something to do with platform compatibility.) R INSTALL -c SJava-version.tar.gz (-c executes a cleanup script which performs the linking) I would doublecheck to make sure you have R compiled as a shared library. Easily- look in R_HOME/bin for libR.so. (or, I assume libR.dll) Hope some of this will help. happy pinball, n I downloaded it and installed it with all the recommended options. I created the LD_LIBRARY_PATH environment variable but my java compiler (latest version) can't find packages like org.omegahat.R.java and cannot resolve symbol (class) like REvaluator, RForeignReference... any idea ? many thanks for answering my last question I promise ! best regards, Anthony ====Nathan Whitehouse Statistics/Programming Baylor College of Medicine Houston, TX, USA nlwhitehouse at yahoo.com work: 1-713-798-9029 cell: 1-512-293-5840 http://rho-project.org: rho- open source web services for R. http://franklin.imgen.bcm.tmc.edu: Shaw laboratory, bcm.