ActiveX

ActiveX is a Microsoft framework for defining reusable software components in a programming language-independent[disambiguation needed] way (i.e. not tied to a particular programming language). Software applications can then be composed from one or more of these components in order to provide their functionality. It was introduced in 1996 by Microsoft as a development of its Component Object Model (COM) and Object Linking and Embedding (OLE) technologies and is commonly used in its Windows operating system. In principle it is not dependent on Microsoft Windows, but in practice, most ActiveX controls require either Microsoft Windows or a Windows emulator. Most also require the client to be running on Intel x86 hardware, because they contain compiled code.

Many Microsoft Windows applications — including many of those from Microsoft itself, such as Internet Explorer, Microsoft Office, Microsoft Visual Studio, and Windows Media Player — use ActiveX controls to build their feature-set and also encapsulate their own functionality as ActiveX controls which can then be embedded into other applications. Internet Explorer also allows the embedding of ActiveX controls in web pages. However, ActiveX will not work on all internet platforms, so using ActiveX controls to implement essential functionality of a web page restricts its usefulness.