Web3.js was created as a way for developers to easily connect their DApps with information on the Ethereum blockchain. Using its modular libraries, developers can interact with smart contracts as if they are JS objects, subscribe to on-chain events, get block state directly from Ethereum nodes, and more. Web3.js is currently migrating to a modernized version built in TypeScript. The library has over 500,000 weekly downloads and is used by some of industry leading projects such as OpenSea.