Myriadcoin is the first coin to implement five different Proof-of-Work hashing alrogithm in the same coin, namely Scypt, SHA256D, Qubit, Skein and Groestl. This multiple hashing algorithm serves to make mining fairer and encourage even distribution. Each algorithm has the same chance of solving the next block and has its own independent difficulty while using the same difficulty adjustment method. Each algorithm aims for a block generation time of 2.5 minutes. Any existing CPU,GPU and ASIC miners can be used to mine Myriadcoin. Over the five algorithms, a block should be found on average every 30 seconds. Every 967680 blocks, the block reward halves in order to reduce inflation. Difficulty is adjusted after every block. Myriadcoin was launched on 23 February 2014.
Grin coin is a private & lightweight open source project based on the mimblewimble blockchain implementation. MimbleWimble is a lightweight blockchain protocol proposed by anonymous author that goes by the name Tom Elvis Jedusor (inspired by Harry Potter) in July 2016. Since then, the proposal has gained a huge following among Bitcoin and privacy advocates. Unlike bitcoin or ethereum, there are no addresses in Grin. In order to transact using Grin, both wallets must communicate with each other online with the results broadcasted to the network. Another key different is that transaction history (sender, receiver, amount) will not be recorded on the blockchain. Due to the removal of these information from the transaction, the data size remains small and that keeps the blockchain lightweight. New nodes can easily join the network without having to download a large blockchain. Grin coin was launched without an ICO, fundraising, or pre-mine. Developers around the world contribute openly with the goal to ensure the coin distribution remains as fair as possible. There are 2 popular wallets widely available to interact with the Grin network. Grin core wallet: https://www.coingecko.com/buzz/how-to-use-grin-wallet-to-send-receive-grin-coins Wallet713: https://www.coingecko.com/buzz/how-to-use-grin-wallet713-to-send-and-receive-grin-coin-step-by-step-guide The consensus algorithm used by Grin is the Cuckoo Cycle proof-of-work based. There are 2 hashing algorithms involved with Grin. Cuckoo-29 is meant for GPU mining while Cuckoo-31 is meant fo ASIC mining. This is a deliberate design to encourage miners to eventually move into ASIC mining for efficiency while keeping it fair at the beginning of the launch. Grin coin has launched its mainnet on 15th January 2019 and is now available for mining and trading.