Hi James, It sounds like the project is being very active. Glad to hear that! No matter how good a mailing list is, in practice, it cannot be the best mailing list for every topic there is. core-libs-dev is no exception. It's good to see you've found another way to make progress on the project.
The question I was going to ask you was on the implementation internals org.reactivestreams.utils.impl.MutexExecutor However, after examining the new repository, I found that not only has the code in question disappeared, but the structure of the project has changed as well. Will the API have the default implementation (ReactiveStreamsEngine)? -Pavel