Eslint

Pluggable linter that statically analyzes JavaScript code to find problems and enforce patterns. Runs in editors and CI pipelines, surfacing issues before runtime while many findings can be auto-fixed with syntax-aware corrections.

ESLint is widely adopted across the JavaScript ecosystem. Sponsors include Chrome, Nx, Indeed, and Contra, and most JavaScript projects depend on it directly or transitively. It differentiates from alternatives like JSLint or JSHint through its plugin architecture: teams can add custom parsers for TypeScript or JSX, preprocessors for non-JS files, and shared rule sets without forking the tool.

Key capabilities:

• Pluggable rules, parsers, and configs with flat config support
• Syntax-aware auto-fix for many rules, avoiding naive find-and-replace errors
• Editor integrations and CI hooks for immediate feedback
• Custom rules and plugins for team-specific or framework-specific checks
• Support for JavaScript, TypeScript, JSX, and other dialects via plugins

Developers use ESLint to enforce style and catch bugs early, keep multi-engineer codebases consistent, and gate pull requests in CI. Integrations with Prettier, typescript-eslint, and framework-specific plugins make it a central piece of the modern JavaScript toolchain.