iExec is an open-source, decentralized cloud computing platform, running on Ethereum blockchain. iExec allows decentralized applications (dApps) an on-demand access to computing resources and technologies on iExec cloud. iExec has built a blockchain network where dApps can take advantage of cost effective and high-performance resources such as servers, databases, SaaS applications, web hosting and computer farms. iExec’s native cryptocurrency — The RLC token is the primary asset used to access services in iExec infrastructure. RLC is short for “Run on Lots of Computers.” iExec is headquartered at Lyon, France. It was founded by Gilles Fedak and Haiwu He, both are serving as Chief Executive Officer and Head of Asian-Pacific Region of iExec, respectively. Oleg Lodygensky is the Chief Technical Officer. Gilles Fedak received his PhD from the University of Paris Sud in 2003, and has been working as INRIA (Inventeurs du Monde Numerique) research scientist at ENS in Lyon, France. Similarly, Haiwu completed his M.Sc. and PhD from the University of Sciences and Technologies of Lille, France. On April 19, 2017, iExec launched its token sale and raised more than $12 million in exchange for 86,999,784 RLC. In order to support dApps, smart contracts, and their platforms, iExec takes processing-intensive computations off-chain so as to keep a blockchain’s on-chain functions running smoothly. To do this, iExec makes use of XtremWeb-HEP, an open-sourced Desktop Grid Software. Desktop Grid computing (also known as Volunteer Computing) pools unused computing resources to be used by applications and platforms, and according to iExec’s whitepaper, XtremWeb-HEP “implements all the needed features” to make this possible on a global scale, including “fault-tolerance, multi-applications, multi-users, hybrid public/private infrastructure, deployment of virtual images, data management, security and accountability, and many more.” Essentially, with this software, dApps can utilize any computing resource in the iExec framework to run their programs. In their whitepaper, the iExec team lays out the project’s competitive landscape and explains these competitors in relation to iExec. They’re quick to note that decentralized cloud storage providers like Filecoin, Storj, and Siacoin are not direct competitors, and it’s easy to see why. While iExec could theoretically take a step in this direction as it matures, it’s not a storage platform; it’s a computing platform. This does put it in competition with other decentralized computing protocols like Golem and SONM. Both of these, however, are taking aim at a different animal. Essentially, they’re both building a decentralized supercomputer on blockchain technology, while iExec is targeting dApp development and sustainability. Both look towards a future of a blockchain-powered, decentralized internet, but their functions, while sometimes similar, are more complementary than conflicting.
QuarkChain is a secure, permission-less, scalable, and decentralized blockchain. One of the goals of QuarkChain is to utilize sharding technology to deliver over 1 million transactions per second (tps). Essentially, QuarkChain markets itself as a peer-to-peer blockchain with a high capacity throughput to help deliver fast and secure decentralized applications. The team behind QuarkChain created this blockchain to resolve the issue of scalability that all the major blockchains are currently facing. The team feels that because of the urgency of this issue, the Bitcoin community simply cannot afford to wait until they all agree on a solution. Instead, they feel that by offering different solutions, such as the one inherent in QuarkChain, this compels the community to split via a hard fork and find the solution that works best. QuarkChain encourages increased decentralization through multiple cheap nodes that then create a cluster that works as a super-full node. This prevents the high expenses associated with super-full nodes when the tps gets high. In terms of protection, all transactions within QuarkChain get the protection of 50 percent of the network’s hash power. This makes a double-spending attack incredibly challenging, particularly when combined with QuarkChain’s decentralized nature. QuarkChain relies on a two-layer blockchain structure. Sharding blockchains known as shards are the first layer, while the second layer is a root blockchain that confirms the shards’ blocks.The major work on QuarkChain began in Q2 2017 with research into the problem of blockchain scalability. In Q4 of that year, the team drafted the whitepaper. In February 2018, it released the white paper and completed verification code 0.1. March 2018 saw the 0.1 versions of both the wallet and testnet. Now in Q2, the team is working on the testnet 1.0 and smart contract 0.1. In Q4 2018, the team will have the QuarkChain Core 1.0, along with the mainnet 1.0 and the SmartWallet 1.0. By Q2 2019, both the SmartWallet and QuarkChain Core will be in their 2.0 versions. QuarkChain is a decentralized blockchain network that aims to resolve the issues of scalability that plague existing networks by using sharding technology. In this way, QuarkChain can dramatically extend the usefulness of blockchain technology since many applications are limited by the scalability of existing blockchain networks. The project is still in progress, but QuarkChain has already made many positive steps and already began invite-based beta testing for the testnet, showing significant progress and potential. The main features of Quarkchain are: 1. Reshardable two-layered blockchain: Quarkchain consists of two layers of blockchains. We apply elastic sharding blockchains (shards) as the first layer, and a root blockchain as the second layer that confirms the blocks from the first layer. The second layer that confirms the blocks from the first layer. The second layer is flexible to be resharded as needed without changing the root layer. 2. Guaranteed security by market-driven collaborative mining: To ensure the security of all transactions, a game-theoretic framework is designed for incentives, where at least 50% of overall hash powers are allocated to the root chain to prevent double spending attack on any transactions. 3. Anti-centralized horizontal scalability: In any blockchain network with a high TPS, a super-full node can be extremely expensive, which encourages centralization. In contrast, QuarkChain allows multiple cheap nodes forming a cluster to replace a super-full node. 4. Efficient cross-shard transactions: Cross-shard transactions in QuarkChain can be issued at any time, and confirmed in minutes. The speed of cross-shard transactions increases linearly as the number of shards increases. 5. Simple account management: There is only one account needed for the entire blockchain (shards) in QuarkChain. All cryptocurrencies from different shards are stored in one smart wallet.