Smart contracts on Ethereum are fully self contained and any information or access to off-chain data is restricted. Tellor solves this problem by creating a system where parties can request the value of an off-chain data point (e.g. ETH/USD) and miners compete to add this value to an on-chain data bank, accessible by all Ethereum smart contracts. Inputs to a data series are secured by a network of staked miners. The main Tellor smart contract creates a time series of each requested data series and aims to become the standard source of high value data for decentralized applications. This oracle, “Tellor”, utilizes similar incentive mechanisms to other cryptocurrency systems through the issuance of Tellor’s token, Tributes, that are used to request a particular data series from miners.
Launched on Dec 25, 2016, Obyte is a distributed ledger based on directed acyclic graph (DAG). Thanks to absence of blocks and miners, access to Obyte ledger is decentralized, disintermediated, free (as in freedom), equal, and open. Obyte is the first DAG based cryptocurrency platform to support dApps. Due to absence of miners and blocks, there is no risk of front-running and other miner manipulation, and dApps are safer and easier to develop than blockchain based dApps. DApps are developed in Oscript - a new language that avoids many unsafe programming patterns common in earlier dApp platforms. Thanks to its safety, Obyte is especially well suited for DeFi apps, some are already available on the platform, such as Discount Stablecoins (https://ostable.org), some are being developed. Other features include: self-sovereign identity, private untraceable currencies, sending crypto to email using textcoins, and extremely small-footprint libraries suitable for small IoT devices.