• Helpers
• Compression (File Compression utilities:  WinZip, 7-zip, etc.), Sounds (.au, .aif, .wav), Pictures&Movies (.gif, .jpg, .mov, mpeg)
• AVI=Audio/Video Interleave for Windows
• MS-Video for Windows, QuickTime Video, MPEG II (Motion Picture Expert Group)
  • Apple QuickTime ... - Uninstall QuickTime immediately!
• Viewers
• Document Viewers (PDF=Adobe Acrobat, MS-Word)
• Presentation Viewers (ASAP WebShow, MS-PowerPoint Animation Player & Publisher)
• Animation Viewers (Shockwave)
• 3D Viewers, Virtual Reality Modelling Language (VRML)

• Plug-Ins
• 3D and Animation, Business and Utilities, Presentation, Audio/Video, Image Viewers

• Java Scripts & Java Applets
• JavaScript is not Java (by Sun).  Don't confuse them.
• Both are programming languages.  Both look somewhat like C++.
• Both are very powerful, but Java is more comprehensive.
• Both can be used either client-side or server-side.

• Flash ...
• MIME
• Multipurpose Internet Mail Extensions
• A standard which enables Internet users to exchange multimedia messages containing enhanced character sets.
• FILExt - The File Extension Source

• PLUG-INS
• Plug-in modules are software programs that extend the capabilities of the browser. Plug-ins are associated with a MIME data type that the browser does not natively support. When the browser encounters an unknown data type from a server, the browser looks for a plug-in that is associated with that MIME type and loads the plug-in.

• INLINE PLUG-INS
• Plug-ins are software programs that extend the capabilities of the browser Navigator in a specific way - giving you, for example, the ability to play audio samples or view video movies from within Navigator.

• SHOCKWAVE BY MACROMEDIA Adobe 
• Shockwave is the industry standard for delivering and experiencing quality interactive multimedia, graphics, and streaming audio on the World Wide Web.
• End of Life (EOL) for Adobe Shockwave - Effective April 9, 2019, Adobe Shockwave will be discontinued and the Shockwave player for Windows will no longer be available for download.
• See also: Flash ...

• HELPER APPLICATIONS
• Helper applications run or display files that aren't integrated into Web pages and don't display inside the Navigator window.
• When the browser encounters a sound, image, or video file, it hands off the data to other programs, called helper applications, to run or display the file.
• Most of these helper apps are shareware or freeware that can be found at various archive sites around the world.
• You can configure them in the Helper Applications dialog box found under Preferences in the Options menu.

Inline Images display in the browser window.
External (linked) Images display in the helper application's window.