Moonriver
Moonriver is intended as a companion network to Moonbeam, where it will provide a permanently incentivized canary network. New code will ship to Moonriver first, where it can be tested and verified under real economic conditions. Once proven, the same code will ship to Moonbeam on Polkadot.
Launching 2021, succeeding Kusama parachain auctions.
Moonriver receives code deployments earlier and launches to Kusama first.
Since Kusama will enable parachain functionality in the first half of 2021, the Moonriver network will be able to deploy as a parachain before Moonbeam deploys to Polkadot. That means developers will have earlier access to Moonriver to start building, experimenting, and launching, and other participants will be able to access DApps and assets on that chain.