ETH SDK is developed by dEth, the developers behind Hardhat, Typechain, and the dEth Tools. ETH SDK allows developers to interact with smart contracts, automatically download ABI's from Etherscan, and generate ethers.js contract wrappers with their API.  Overall, ETH SDK reduces the ceremony needed when interacting with Ethereum contracts with Javascript and Typescript, and makes for better developer experience by ensuring contracts have type information so that your IDE can assist you.