Hi, We are using gcc 4.1.2 remotely on our RHEL 3.0 OS to build our current releases and plan to move our base OS to RHEL 4.0 on 2008. We will continue to use the same version of gcc 4.1.2 from the remote location. Since not all products will move at the same pace, can we use the object code built on RHEL 3.0 to link with the object code build on RHEL 4.0 (both built by gcc 4.1.2)? We have both C and C++ source code and we will always do the link step on RHEL 4.0. Also we use the libgcc_s.so.1, libstdc++.so.6, etc. from our own gcc 4.1.2 hierarchy at run-time. regards Satya