With the proof-of-work and proof-of-stake proving to be the two dominant algorithm in the cryptosphere, the former being adopted in the creation of bitcoin the world's first ever digital currency, with peercoin adopting the latter. Proof-of-stake has since proven to have an edge over its counterpart by providing the incentive features that allows holders of coins built on the proof-of-stake to earn some extra token as a reward for holding the coins and also provides inherent security for coins developed with the algorithm.
ONEX network
ONEX network is a proof-of-stake smart contract that looks to be the first network to bring the proof-of-stake algorithm to the Ethereum Classic platform.