ActiveX is a deprecated software framework created by Microsoft that adapts its earlier Component Object Model (COM) and Object Linking and Embedding (OLE) technologies for content downloaded from a network, particularly in the context of the World Wide Web. It was introduced in 1996 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 platforms, so using ActiveX controls to implement essential functionality of a web page restricts its usefulness.
Faced with the complexity of OLE 2.0 and with poor support for COM in MFC, Microsoft simplified the specification and rebranded the technology as ActiveX in 1996. Even after simplification, users still required controls to implement about six core interfaces. In response to this complexity, Microsoft produced wizards, ATL base classes, macros and C++ language extensions to make it simpler to write controls.
Starting with Internet Explorer 3.0 (1996), Microsoft added support to host ActiveX controls within HTML content. If the browser encountered a page specifying an ActiveX control via an
OBJECT tag, it would automatically download and install the control with little or no user intervention. This made the web "richer" but provoked objections (since such controls, in practice, ran only on Windows, and separate controls were required for each supported platform: one for Windows 3.1/Windows NT 3.51, one for Windows NT/95, and one for Macintosh F68K/PowerPC.) and security risks (especially given the lack of user intervention). Microsoft subsequently introduced security measures to make browsing including ActiveX safer.
- digital signing of installation packages (Cabinet files and executables)
- controls must explicitly declare themselves safe for scripting
- increasingly stringent default security settings
- Internet Explorer maintains a blacklist of bad controls
In October 1996, Microsoft released a beta version of the ActiveX Software Development Kit (SDK) for the Macintosh, including a plug-in for Netscape Navigator on the Mac, and announced its plan to support ActiveX on Solaris later that year.
ActiveX was controversial from the start; while Microsoft claimed programming ease and good performance compared to Java applets in its marketing materials, critics of ActiveX were quick to point out security issues and lack of portability, making it impractical for use outside protected intranets. The ActiveX security model relied almost entirely on identifying trusted component developers using a code signing technology called Authenticode. Developers had to register with Verisign (US$20 per year for individuals, $400 for corporations) and sign a contract, promising not to develop malware. Identified code would then run inside the web browser with full permissions, meaning that any bug in the code was a potential security issue; this contrasts with the sandboxing already used in Java at the time.
In 2015, Microsoft announced that their new web browser and Internet Explorer replacement, Microsoft Edge, will not support ActiveX, which they described as a "legacy technology".
ActiveX in non-Internet Explorer applications
It may not always be possible to use Internet Explorer to execute ActiveX content (e.g. on a Wine installation), nor may a user want to.
- FF ActiveX Host can run ActiveX controls in Mozilla Firefox for Windows.
- Mozilla ActiveX Control was last updated in late 2005, and runs in Firefox 1.5.
- MediaWrap for Firefox was last updated on 12 June 2008, and will run in Firefox 1.5 to 3.5.*.
Other ActiveX technologies
Microsoft has developed a large number of products and software platforms using ActiveX objects. They are still used (e.g., websites still use ASP.):
- Active Messaging, later renamed Collaboration Data Objects
- Active Scripting, a technology for scripting ActiveX objects
- Active Server Pages (ASP)
- ActiveMovie, later renamed DirectShow
- ActiveX Data Objects (ADO)
- ActiveX Streaming Format (ASF), renamed Advanced Streaming Format, then to Advanced Systems Format
- Active Setup
- Active Template Library (ATL)
- Google Native Client, an alternative development from Google
- IUnknown interface
- NPAPI, an alternative interface for web-browser plugins
- OLE Automation
- Windows DNA
- Introduction to ActiveX Controls at microsoft.com, accessed 18 January 2008
- Anderson, Jerry (1997). Activex Programming with Visual C++. Que. ISBN 978-0789710307.
- Seoul poised to remove ActiveX software from public websites. 3 March 2015.
- Gregg Keizer (10 May 2015). "Microsoft nixes ActiveX add-on technology in new Edge browser". Computerworld.
- "Using ActiveX with LabVIEW – Examining Mission Editor Version 1.0". NI Developer Zone. National Instruments. 13 August 2007. Retrieved 2009-03-12.
The term ActiveX surfaced in the Microsoft world in early 1996.
- "Microsoft announces ActiveX Technologies". Microsoft PressPass. Microsoft. 12 March 1996. Retrieved 2009-03-12.
Microsoft Corp. today announced ActiveX ... Technologies, which make it easy for the broadest range of software developers and Web designers to build dynamic content for the Internet and the PC. ... ActiveX Technologies form a robust framework for creating interactive content using software components, scripts and existing applications. Specifically, ActiveX Technologies enable developers to build Web content easily using ActiveX Controls (formerly OLE Controls), active scripts and active documents. ... ActiveX Technologies are available in the form of the Microsoft ActiveX Development Kit, which is being distributed to more than 4,000 developers attending the Professional Developers Conference in San Francisco today.
- "Activating ActiveX Controls". Activating ActiveX Controls. Retrieved 2009-06-16.
- Quinlan, Tom (28 October 1996). "MacOS will get access to ActiveX". InfoWorld. p. 48.
- "Documentation for ActiveX Core Technology". The Open Group. Retrieved 7 August 2012.
- "ActiveX technology: You can't go there today". InfoWorld. 19 May 1997. pp. 90 ff.
- Dugan, Sean (19 May 1997). "Exposing the ActiveX security model". InfoWorld. p. 98.
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