* Try to optimize communications when bookkeeping.
    Add a 'credit' counter for each neighbor.
    Do not send more real_load than (debt - credit).

* Support heterogeneous platforms?
   Not sure yet.
   Should be doable if each process also sends its speed to its neighbors.

* Add options -j/-J: minimum number of iterations?

* Add options -f/-F: termination based on flops achieved?

* Choose a license before making the code public.
   CeCILL-B?

* Translate french parts in english (README, QUESTIONS, ALGORITHMS, ...)
   Not urgent.

* Add synchronized mode?
   No.

* Add a variant to (not) change neighbor load information at send?
   No.