Polkadot
Multi-chain network for blockchain interoperability — parachains and relay chain.
Polkadot (DOT) was created by Gavin Wood (Ethereum co-founder) to solve the interoperability problem — the ability of different blockchains to communicate.
Architecture:
•Relay chain — central chain providing security to all parachains
•Parachains — specialized chains connecting to relay chain
•Bridges — connections to external chains (Ethereum, Bitcoin)
DOT token:
•Staking for network security (~14% APY)
•Governance — voting on protocol changes
•Parachain slot auctions — projects lease slots through DOT bonding
Ecosystem: Acala (DeFi), Moonbeam (EVM compatibility), Astar (smart contracts). Substrate framework enables rapid construction of new blockchains.