Dear all, attached is a first, very rough draft of a proposal for sparse, persistent, nonblocking collectives that Torsten and I have been discussing during IPDPS last week (with some local discussion here afterwards). It may serve to start discussion - either Torsten or I can present the gist of it during the group slot wednesday (not much time there, I just realize) Sorry for the rough state of it all... (note: it is *not* (yet) LaTeX) Jesper