xo is a zero-config linting tool and ESLint wrapper that provides opinionated default rules for JavaScript and TypeScript. It functions as a static analysis tool to enforce code style and readability standards immediately upon installation without requiring manual configuration.
The tool distinguishes itself by providing a zero-config development workflow that eliminates the need for complex configuration files. It supports incremental codebase cleanup by allowing users to ignore known violations through a suppressions file, facilitating the gradual adoption of strict rules in existing projects.
Beyond basic linting, it includes capabilities for automated code formatting, TypeScript static analysis, and the ability to automatically fix syntax and style errors. It also manages parser project resolution for TypeScript and integrates with external plugins to analyze framework template files.
Performance is supported through the caching of linting results to avoid re-processing unchanged files.