HipG

Its basic property is that it does not have supersteps. Instead the computation is coordinated by synchronizers which can also spawn sub-synchronizers. By this way, there's no more a global barrier but the algorithm can specify different barriers to which subsets of the vertices can synchronize. The idea is to allow a more fine-grained synchronization mechanism, to avoid many vertices to idle waiting for unrelated vertices to finish their computation.

Unlike Signal/Collect and Pregel which can only control individual vertices, global execution can be controlled thanks to synchronizers in HipG.

But it is hard to comprehend the usage of these sub-synchronizers mechanism. Who will manage which vertices?

It processes vertices not with vertex id order, instead they start from a pivot vertex and compute neighbors recursively until all are processed.

It can create the graph on-the-fly. This is especially important for model checking, search trees and so on. I think the biggest strength of HipG is this property.