Jakub - Thanks for the explanations. I've put in -fPIC in my HDF package, which only produces static libs so users are forced to use them in shared objects that use those libraries. -- Orion Poplawski System Administrator 303-415-9701 x222 Colorado Research Associates/NWRA FAX: 303-415-9702 3380 Mitchell Lane, Boulder CO 80301 http://www.co-ra.com