Wiki Plugins (Wiki) -
For other uses, see Plug in.
A plugin (plug-in, addin, add-in, addon, add-on or snap-in; but see extension) is a computer program that interacts with a host application (a web browser or an email client, for example) to provide a certain, usually very specific, function "on demand". Applications support plugins for many reasons. Some of the main reasons include: enabling third-party developers to create capabilities to extend an application, to support features yet unforeseen, reducing the size of an application, and separating source code from an application because of incompatible software licenses.
Examples of applications and their plugins include:
Email clients use plugins to decrypt and encrypt email (Pretty Good Privacy)
Graphics software use plugins to support file formats and process images (Adobe Photoshop)
Media players use plugins to support file formats and apply filters (foobar2000, GStreamer, Quintessential, VST, Winamp, XMMS)
Packet sniffers use plugins to decode packet formats (OmniPeek)
Remote sensing applications use plugins to process data from different sensor types (Opticks)
Software development environments use plugins to support programming languages (Eclipse, jEdit, MonoDevelop)
Web Browsers use plugins to play video and presentation formats (Flash, QuickTime, Microsoft Silverlight, 3DMLW)
Some digital mixing consoles allow plugins to extend features such as reverberation effects, equalization and compression.