Cardano (ADA)

A project where engineering starts from peer-reviewed research: the Ouroboros consensus protocol was published and picked over by academics before it was implemented. Hence the unhurried release cadence the network is regularly criticised for.

Consensus runs on proof of stake: time is cut into slots, the right to propose a block is drawn in proportion to stake, and a holder can delegate that stake to a pool without handing over the funds or locking them — they stay available at any moment. Accounting uses an extended unspent-output model rather than accounts, so the outcome of a contract is predictable before the transaction is sent and the fee is known in advance.

Supply is capped at forty-five billion coins. A share of fees flows into a network treasury that funds community proposals by vote, and development is carried in parallel by several independent organisations rather than a single company. Smart contracts did not arrive at launch: for several years the chain settled transfers and nothing more, which shaped its reputation for a long time.

The output-based accounting model buys predictability but complicates porting applications written for Ethereum's familiar account model.