Flex SDK

The Flex SDK (Software Development Kit) is a collection of tools and libraries that helps developers create rich internet applications, primarily using Adobe's Flash technology. It allows for building interactive and visually engaging web applications that can run in browsers or on desktop environments. Flex SDK includes components for designing user interfaces, managing data, and integrating with web services. It uses ActionScript and XML to define application logic and layout. Although its popularity has decreased with the rise of modern web technologies, it played a significant role in the development of complex web applications in the past.