Composer is an application-level package manager for the PHP programming language that provides a standard format for managing dependencies of PHP software and required libraries. It manages them on a per-project basis, installing them in a directory (e.g. vendor) inside your project.
PurgeCSS is a tool to remove unused CSS. When you are building a website, you might decide to use a CSS framework like TailwindCSS, Bootstrap, MaterializeCSS, Foundation, etc... You will only use a small set of the framework but a lot of unused CSS styles will be included.
PurgeCSS analyzes your content and your CSS files. Then it matches selectors used in your files with the ones in your content files. It removes unused selectors from your CSS, resulting in smaller CSS files. PurgeCSS comes with a JavaScript API, a CLI and plugins for popular build tools.
NPM stands for Node Package Manager, which is an application and repository for developing and sharing JavaScript code. To publish and install packages to and from the public NPM registry or a private NPM registry, you must install Node.js and the NPM command line interface using either a Node version manager or a Node installer.
Redis is an open-source in-memory key-value data store. It can be used as a database, cache, message broker and supports various data structures such as Strings, Hashes, Lists, Sets, etc... Apart from its performance and flexibility, Redis stands out with its wide language support, high availability, and automatic partitioning.
Symfony is a PHP web application framework and a set of reusable PHP components/libraries. Symfony aims to speed up the creation and maintenance of web applications and to replace repetitive coding tasks. It's also aimed at building robust applications in an enterprise context, and aims to give developers full control over the configuration: from the directory structure to the foreign libraries, almost everything can be customized.
