I'm still trying to access the relevant papers, but from bits of discussions here it seems to me that the difference between the Julia scheduler and cilk is that the former will try to distribute sibling leaf tasks among executors enforcing as close as a global depth first view as possible, while cilk does depth first on each executor but different executors will be exploring distinct the problem space branching off as close to the root as possible (due to the steal the oldest ancestor behaviour). It is a compromise between better cross executor cache locality and increased contention I guess.