A helper application is an external viewer program launched to display content retrieved using a web browser

Web browser

A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier and may be a web page, image, video, or other piece of content...

. Some common examples include Windows Media Player

Windows Media Player

Windows Media Player is a media player and media library application developed by Microsoft that is used for playing audio, video and viewing images on personal computers running the Microsoft Windows operating system, as well as on Pocket PC and Windows Mobile-based devices...

 and QuickTime Player for playing streaming content.

Unlike a plugin(whose full code is included into browser code), a small line is added to the browser code to tell it to open a certain helper application in case it encounters a certain file format.

See also

• ActiveX control
• Object Linking and Embedding
  Object Linking and Embedding
  Object Linking and Embedding is a technology developed by Microsoft that allows embedding and linking to documents and other objects. For developers, it brought OLE Control eXtension , a way to develop and use custom user interface elements...
  
  
• Overlay (operating system)
  Overlay (operating system)
  In operating systems, an overlay is when a process replaces itself with the code of another program. On Unix-like systems, this is accomplished with the exec system call....
  
  
• Plug-in (computing)
• shell script
  Shell script
  A shell script is a script written for the shell, or command line interpreter, of an operating system. It is often considered a simple domain-specific programming language...
  
  
• Video player (software)
  Video player (software)
  A video player is a kind of media player for playing back digital video data from media such as optical discs , as well as from files of appropriate formats such as MPEG, AVI, RealVideo, and QuickTime....
  
  
• XCMD