New development of new protocol for intra blockchain communication: http://blocknet.co/#xbridge
Not limited to decentralised exchanges only, sounds a bit something in between a cross-blockchain peerassets and an app platform talking across different chains.
They have their marketing in order with a flashy website, but not much concrete to offer yet imo. Promising, is the best I can make of it. Haven't dived deep into it, but thought it to be worth sharing.