Groestlcoin is a blockchain payment protocol with a number of technical innovations and an active developer community. Groestlcoin was the first coin that activated SegWit and supports the Lightning Network. Transaction fees are very low and it claims to have instant payments. It is also one of the only coins that can be sent over SMS.
Groestlcoin's active developer community has made the payment protocol very adaptable, and it a popular coin among many crypto investors. Groestlcoin has an ASIC resistant Proof-of-Work consensus mechanism.

Bitcoin Diamond is a hardfork of Bitcoin that was created in 2017. Although the network's code preserves much of Bitcoin's original features, it aims to improve transaction speeds by implementing the Lightning network and increasing the storage capabilities of each block. The Lightning Network is a second layer payment protocol that works on the Bitcoin blockchain and is designed to place a large portion of the transaction data outside of the blockchain.

Nimiq is a censorship-resistant cryptocurrency that is designed to run in the user's browser. Nimiq's focus is on usability and the browser first approach allows coin holders to participate in their payment network more easily. Nimiq uses a Merkle-based accumulator to store accounts and balances, and has a Non-Interactive Proofs of Proof-of-Work consensus mechanism.