Viacoin is an open source cryptocurrency based on the Bitcoin protocol. Viacoin has a 24 second block time and relatively fast transaction times. It can handle 175 transactions per second without scaling through Segwit or the Lightning Network. The fast transaction times make Viacoin a good option for sending micropayments. The platform also enables users to perform cross-chain atomic swaps between different cryptocurrencies, without a centralized exchange. Viacoin has an Auxiliary Proof-of-Work (AuxPoW) consensus mechanism that allows miners to mine multiple coins, that use the Scrypt algorithms, at the same time. Viacoin's smart contract platform, Rootstock, is compatible with Ethereum smart contracts.

NEM is a cryptocurrency and blockchain platform that allows multiple ledgers on the same blockchain. NEM Smart Assets are used to create mosaics for any asset. Transaction fees are paid with NEM's native currency, XEM. NEM originally began as a community-oriented cryptocurrency that was built from the ground up in the Java programming language.
NEM's goal is to achieve widespread distribution through improved scale and speed. It pioneered several blockchain features such as its proof-of-importance (POI) consensus algorithm, encrypted messaging, a unique reputation system, and multi-signature accounts.
NEM is also developing a commercial blocckahin called Mijin, that is currently being tested by several companies and financial institutions.
In early 2018, approximately $400 million worth of XEM were stolen from a Japanese exchange called Coincheck, that was the victim of huge hack. The exchange failed to implement proper security for this coin protocol, and the hackers only stole XEM coins as a result. Instead of creating a fork to deal with this issue, NEM set up an automated tagging system that flagged these funds. NEM then stopped tracking these stolen coins

Flash Coin is a cryptocurrency designed to be used for everyday transactions. Flash's blokchain has a delegate-based consensus model that depends on elected delegates to verify transactions. These delegates elect 25 Miners who create new blocks on the blockchain. Each miner is given a specific time where they can mine a block. The Flash Coin algorithm also introduces a concept called Consensus Height, which refers to the moment when more than half of elected miners have created a block on top of another block in the chain.