HTMLCOIN is a Proof-of-Stake (PoS) blockchain platform focused on enabling the practical applications of smart contracts. The HTML blokchain is a hybrid of Ethereum and Bitcoin, and also combines elements of other blockchain infrastructures.

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.

EOS is a blockchain development platform created by Block.one. Its goal is to become an all purpose operating system for blokchain applications. EOS allows developers to make underlying blockchains and create decentralized application more easily. It was designed from the ground up, to be more scalable and faster than other blockchain platforms. This allows for greater throughput, with more transactions per second, and much lower transaction fees. EOS tokens serve as the native currency. The network has a Delegated Proof-of-Stake (dPoS) consensus mechanism. Transactions are verified by 21 block producers that are chosen through a voting process that is designed to encourage community participation.