ESLint

ESLint is an extensible static analysis tool for JavaScript and TypeScript, created by Nicholas C. Zakas in 2013. It identifies problematic patterns and enforces coding standards through a configurable rule system. ESLint's flat configuration format (introduced in v9) simplifies setup with a single eslint.config.js file.

With auto-fix support, ESLint can automatically correct many issues during development or in CI. The plugin ecosystem extends it with framework-specific rules for React, Vue, and other libraries. Combined with Prettier for formatting, ESLint handles the code quality and correctness side of static analysis. The project is open source on GitHub.