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.

Connect Coin is an Ethereum based token that was created by a company in Tanzania called Cryptocurrency International. Their focus is on serving as an alternative payment method for e-commerce. They are also developing crypto debit cards called Connect Cards.

Primecoin is a cryptocurrency based on finding prime numbers. Identifying prime numbers plays a central role in cryptography. Primecoin's unique Proof-of-Work (PoW) consensus mechanism is able to increase transaction speeds and improve energy efficiency.
The network searches for special prime number chains known as Cunningham chains and bi-twin chains, which are of interest in mathematical research.