Express.js Web Framework

Express.js is a minimalist, unopinionated, and flexible Node.js web application framework, designed for building robust APIs and web applications. It provides a thin layer of fundamental web application features atop Node.js's built-in HTTP module, emphasizing speed and extensibility through its middleware-centric architecture. The current stable release is v5.2.1, with the v5 branch representing a major overhaul focused on simplifying the codebase and improving security. The v4.x branch (currently v4.22.1) is also actively maintained, primarily for security patches and critical bug fixes, serving projects that haven't yet migrated to v5. Its unopinionated nature contrasts with more prescriptive frameworks, offering maximum flexibility in project structure and choice of components, allowing developers to easily extend functionality for tasks like routing, parsing request bodies, handling sessions, and serving static files.