The main differences between the three can be described along two axes: buffering/single-subscriber vs. non-buffering/multi-striver, and synchronous vs. asynchr

The main differences between the three can be described along two axes: buffering/single-subscriber vs. non-buffering/multi-striver, and synchronous vs. asynchronous. You don't really need three separate interfaces for this. Dart's Streams can cover all cases depending on how you create the source StreamController. I asked some of the people behind the specs and they felt if was too complicated to have one interface cover the use cases. I tend to think it's more complicated now. I can't trivially write code to handle all interfaces without explicitly thinking and opting in to it.