Cardano is a proof-of-stake blockchain platform built on peer-reviewed academic research. Founded by Ethereum co-founder Charles Hoskinson, it takes a methodical, research-first approach to development. Its Ouroboros consensus mechanism was the first provably secure PoS protocol.
Polkadot is a Layer 0 multi-chain network that allows different blockchains to interoperate. Created by Ethereum co-founder Gavin Wood, it uses a relay chain and parachain architecture letting multiple specialised blockchains run in parallel and communicate securely.
Satoshi Nakamoto is the pseudonymous creator of Bitcoin and the author of the Bitcoin whitepaper. Their true identity remains one of the greatest mysteries in technology. Satoshi mined approximately 1 million Bitcoin in the early days before disappearing from public life in 2010.