Quarkcoin is a coin which increases security by using 9 rounds of hashing from 6 different hashing algorithms - blake, bmw, grøstl, JH, keccak, skein. 3 of the hashing rounds apply a random hashing function. This compares with Bitcoin's solitary use of SHA-256 algorithm. There is no pre-mine for this coin. A new block is generated every 30 seconds and 2048 Quark is given out as reward per block at the beginning. This reward halves every 60480 blocks or roughly every 3 weeks. The initial supply of Quark is 247 million and this is expected to be mined in roughly 6 months since launch date. The supply will then continue to increase at an inflationary rate of 0.5% per year. Quarkcoin was launched on 21 July 2013.
Zen is a decentralized financial platform, built from scratch with the goal of providing people with a secure, scalable and useful infrastructure for creating their own financial instruments, and trading them directly without intermediaries.The Zen blockchain is secured by multiple proof-of-work algorithms, with token-holder voting on the balance between them. Multi-hash mining creates robust incentives for miners to deliver efficient, reliable security.Zen smart contracts are written and secured by a subset of the F* functional programming language, allowing users to: A) Prove the amount of resources a contract will consume and provide the necessary fees for running the contract to miners, removing the need for a “gas” based system.B) Prove their contracts meet a given specification, meaning they can prove the contract will definitely do (or not do) something given a specific set of parameters.The Zen platform comes with a built-in solution for oracles, which provide contracts with useful real world data.Finally, Zen is integrated with the Bitcoin blockchain, allowing contracts to observe and respond to native bitcoin transactions