HPC scenario

Has anyone used VisAD for visualization of data from a legacy parallel
application - as opposed to a Java app?
E.g., I have an app written in Fortran, using MPI, and would like to hear
ideas for getting data from such an app into VisAD for on-the-fly
visualization.
Recently I've used the CUMULVS pkg from ORNL to allow for this data exchange
between an app and a front-end viewer written in C++.  CUMULVS allows for
dynamic attachment of a (vis) process to a running simulation (via PVM).

thanks,
Randy