Hi Bruce, Just noticed your post here. We’ve added a bit more info on hyperobjects: • http://www.cilk.com/resources-for-multicoders/for-developers-only/ • http://web.cilk.com/_packages/documentation/ (section on REDUCERS) • Some examples: http://www.cilk.com/resources-for-multicoders/for-developers-only/ Cheers, ilya