ActiveX is a framework for defining reusable software components in a programming language independent way. Software applications can then be composed from one or more of these components in order to provide their functionality.[1]
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, although the technology itself is not tied to it.
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 embedding ActiveX controls onto web pages.
ActiveX controls
ActiveX controls — small program building blocks — can serve to create distributed applications that work over the Internet through web browsers. Examples include customized applications for gathering data, viewing certain kinds of files, and displaying animation.
One can compare ActiveX controls in some sense to Java applets: programmers designed both of these mechanisms so that web browsers could download and execute them. However, they also differ:
- Java applets can run on nearly any platform, while ActiveX components officially operate only with Microsoft's Internet Explorer web browser and the Microsoft Windows operating system.[2]Malware, such as computer viruses and spyware, can be accidentally installed from malicious websites using ActiveX controls (drive-by downloads).
Programmers can write ActiveX controls in any language that supports COM component development, including the following languages/environments:
- C++ either directly or with the help of libraries such as ATL or MFC[3]
- Borland Delphi
- Visual Basic
Common examples of ActiveX controls include command buttons, list boxes, dialog boxes, and the Internet Explorer browser.
