Speaking for the SiCortex MPI implementation (which is a derivative of MPICH2): I expect that implementing the const proposal will be straightforward in our case. Our MPID implementation already uses const when referring to send buffers, and casting is not necessary for software layers below that. If we need to demonstrate another implementation of this, I can attempt to apply the MPICH2 patch to our sources. But I don't expect to learn anything from doing that, as all the complexity should be in getting the patch to apply. SiCortex supports this proposal for 2.2. -dg -- David Gingold Principal Software Engineer SiCortex Three Clock Tower Place, Suite 210 Maynard MA 01754 (978) 897-0214 x224 *