
   This directory will contain various PETSc user contributed preconditioners
that users have found useful. Often they are not well optimized and may contain 
bugs. If after testing, one of these suits your needs in terms of convergence
feel free to further optimize the code and send it back to use for future
inclusion or let us know and we may be able to optimize it for better
performance.

   WARNING: the preconditioners in this directory are NOT ACTIVELY MAINTAINED
            or TESTED by the PETSc development team. If you provide updates and 
            fixes we will include them in our next release and we will attempt to
            help you with them, but they have a lower priority then the base
            routines in PETSc.
