TrumpCoin is a cryptocurrency that was created to support Donald Trump. Their marketing materials do not provide specific details about what they hope to achieve, or why they need a blockchain-based digital currency. TrumpCoin has a hybrid Proof-of-Work (PoW) and Proof-of-Stake (PoS) consensus mechanism.

MonaCoin is the first alternative cryptocurrency developed in Japan. It is based on the popular Japanese character, Mona. MonaCoin has a Proof-of-Work (PoW) consensus mechanism and uses a version of the Lyra2RE mining algorithm that was first used by Vertcoin.
MonaCoin has an enthusiastic user base that has developed a variety of Mona-based web applications and services. MonaCoin holders also use the coin as a tipping system.

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.