The web programming language primarily used for server-side scripting is PHP. PHP (Hypertext Preprocessor) is widely adopted for building dynamic web applications due to its ease of use and integration with databases. It allows developers to create interactive and data-driven websites efficiently. PHP is a vital component of many popular web technologies and content management systems, enhancing web functionality and user experience. Its versatility and strong community support make it a preferred choice for server-side development in the web programming landscape.