OKCash is a Proof of Stake cryptocurrency that was released under the MIT licence.

Feathercoin is a PoW coin with a fast block processing time. The project was developed with the goal of creating a user friendly coin with fast transaction times and low fees. The Feathercoin network features Automatic Checkpointing (ACP), which is used to prevent 51% attacks. ACP creates a new checkpoint every 5 blocks, protecting the history of the Feathercoin blockchain.

Peercoin is the first Proof-of-Stake (PoS) cryptocurrency. It was created in 2012 and is one of the oldest and most reliable cryptocurrency networks in the crypto sector. The protocol was developed by Sunny King and Scott Nadel, both of whom are anonymous. Sunny King also created Primecoin and VEE.
Peercoin’s PoS consensus mechanism is now widely used in the blockchain space, and allows every network participant to be both a miner or an owner. The project is focused on creating a cryptocurrency platform that will be stable, secure, energy efficient, and distributed fairly.