ActiveX
ActiveX is a Microsoft technology framework that enables interactive content and software components to be embedded within web pages or desktop applications, primarily using Component Object Model (COM) for interoperability. It was widely used in the 1990s and early 2000s to add functionality like animations, multimedia, and interactive forms to Internet Explorer and other Windows-based programs. However, it has largely been deprecated due to security vulnerabilities and the shift towards modern web standards.
Developers should learn ActiveX primarily for maintaining or migrating legacy systems, such as old enterprise applications or intranet sites that still rely on it for specific functionalities like document viewing or custom controls. It is also relevant for understanding historical web development practices and COM-based architectures, but modern alternatives are strongly recommended for new projects due to better security and cross-platform support.