Bootstrap

Bootstrap is an open-source front-end toolkit for developing with HTML, CSS, and JavaScript. It is designed to help developers build responsive, mobile-first web interfaces quickly by providing a cohesive set of styles and components. The framework includes a responsive grid system, prebuilt UI components such as navigation bars, forms, buttons, cards, modals, and alerts, as well as JavaScript plugins for interactive features. It also offers a wide range of utilities for spacing, typography, colors, and layout.

Bootstrap was created by Mark Otto and Jacob Thornton at Twitter and released publicly in 2011 as Twitter Bootstrap. It has since evolved through multiple major versions and is maintained as an open-source project with contributions from a broad community. Version 5, the current major release, emphasizes a CSS-only approach and removed a dependency on jQuery, introducing modern CSS features and improved theming via Sass variables.

Using Bootstrap typically involves including its CSS and JavaScript either from a CDN or by installing via package managers such as npm or Yarn. Developers apply Bootstrap classes to HTML elements to achieve layout and styling, and can customize the build by modifying Sass variables and recompiling. The framework is widely used for rapid prototyping and production sites, supported by extensive documentation and a large ecosystem of themes and extensions. While popular, Bootstrap can lead to a uniform look or heavier pages if not carefully customized.