Litecoin is a crytptocurrency that was created to serve as the “silver” to bitcoin’s "gold." It is based on the core Bitcoin protocol, but was designed with several key features that provide it with advantages over Bitcoin.
Litecoin has significantly reduced transaction times by limiting the target block processing time to 2.5 minutes. It also has a total coin supply that is 4 times larger, and utilizes a different hashing algorithm called Scrypt, that requires a smaller workload and less computation power than Bitcoin's SHA-256 algorithm. This enables much faster transactions at a much lower cost to users. These features make Litecoin easier to use and to mine. Since its creation, Litecoin has gained a large market cap and widespread adoption among cryptocurrency users in need of a coin for everyday transactions.

Qtum has been described as a hybrid between Ethereum and Bitcoin. Qtum is a smart contracts platform that places a strong focus on value transfers as well as decentralized apps. Qtum enables users to create smart contracts on the platform and conduct cryptocurrency transactions.
Qtum has a Proof-of-Stake (PoS) consensus algorithm. Several decentralized apps are already using the platform.

Eternal is a Japanese cryptocurrency project that consists of Eternal Coin (XEC) and Eternal Token (XET). The project appears to be primarily focused on remittance payments, but can also be used as a medium of exchange for other purposes. XEC holders receive weekly dividend payments, and can only be traded through the company's authorized exchanges. XET was created to allow users to trade XEC on other crypto exchanges. 1 XET=10 XEC.