Per request at the Louisville meeting, I've wiki-written up and
recorded a screencast showing how some of us have been using Mercurial
in conjunction with SVN for Open MPI development.
A wiki page describing everything (including some pretty pictures) is
The first screencast is here:
If I get time, I'll make another screencast showing how to make a
repository on www.open-mpi.org for sharing between Open MPI developers.