Nex is a new design to crypto exchange: a decentralized exchange with an off chain matching engine. The idea is to combine the fact that holder should have control of their tokens (as in Dex) but not sacrifice matching engine performance and sophistication (as in centralized exchanges).
The secret sauce of this hybrid creation is on a provable deterministic relation between off-chain matched trades and on chain transaction record.
By running a public specified deterministic protocol, that relation can make sure also fair price matching and on chain settlement.
Initially running on NEO, they plan to include Ethereum and other chains in future development.
NEX, Neon Exchange token, is entitled of a share of fees by their NEX on stake, similar to GAS on NEO.