Underscores is a minimal starter theme designed for developers who build custom themes from the ground up. It provides a clean, standards-compliant foundation that is meant to be modified and extended, not used as a parent theme.

Key features include:

• Lean, Modern Templates: A just-right amount of well-commented, semantic HTML5 templates that serve as a solid starting point without unnecessary bloat.
• Organized Starter CSS: Smartly structured CSS in the main stylesheet helps you implement your design quickly, with two sample layout files for sidebars.
• Custom Template Tags: Functions kept in separate files prevent code duplication and help keep your template files clean and maintainable.
• Responsive Navigation: Includes a JavaScript file that converts the main menu into a toggled dropdown on small screens, providing a responsive foundation ready for styling.
• Helpful Utilities: Comes with extras like a 404 template, optional custom header code, and small helper functions to improve the theming workflow, all licensed under GPL.