I thought this might be of interest to some of you. New Java releases are normally upwards binary-compatible with prior releases with only few minor/niche exceptions. This implies that one should normally be able to use recent JVM versions to run MonetDB's (JDBC) class/jar files, even if these were compiled with an older JDK version. See: http://java.sun.com/j2se/1.5.0/compatibility.html and: http://java.sun.com/javase/6/webnotes/compatibility.html#binary Note that the opposite does not hold: class/jar files cannot be run with a JVM older than that from the JDK used to compile them. (Every newer JDK marks its generated class files with a different class file version number, which is checked by the JVM.) I hope this helps. Sander Kruseman