One alternative that I like and it integrates well with mpi
is the global arrays toolkit
http://www.emsl.pnl.gov/docs/global/
--
Jaime D. Perea Duarte. <jaime at iaa dot es>
Linux registered user #10472
Dep. Astrofisica Extragalactica.
Instituto de Astrofisica de Andalucia (CSIC)
Apdo. 3004, 18080 Granada, Spain.