Inferno's <{} construct dispatches processes in parallel, and gathers output in coherent blocks. I use it in credo to parallelize all the dependencies for a target. I rely on mutual exclusion to avoid building a target twice at the same time, and on cached checksums to avoid rebuilding when there have been no changes. See the sh-inferno scripts map, credeper, and cresum in the project http://github.com/catenate/credo
