When developing server software, you need to use a framework or library to simplify and speed up the process. A framework is a collection of pre-written code, tools, and conventions that provide a structure and standard way of developing your server software. A library is a collection of reusable code, functions, and modules that provide specific functionality or features for your server software. Popular frameworks and libraries for server software development include Spring Boot, Express, Django, Flask, Laravel, and React. Spring Boot simplifies the development of Java-based server applications with auto-configuration, dependency injection, embedded servers, and other features. Express simplifies the development of Node.js-based server applications with routing, middleware, error handling, and other features. Django simplifies the development of Python-based server applications with models, views, templates, authentication, administration, and other features. Flask simplifies the development of Python-based server applications with a minimal and flexible core with extensions for various features. Laravel simplifies the development of PHP-based server applications with routing, controllers, models, views, authentication validation, and other features. React is a library that simplifies the development of user interfaces for server-rendered web applications with components, hooks, state management, and other features.