In many ways, the functionality of the MythTV frontend is defined by its many plug-in applications. These software modules build upon the underlying video capture and audio playback foundation at MythTV's very core. Plug-ins take the basic functionality available from the MythTV front end with which users interact, and extend it in all kinds of interesting and sometimes surprising ways.
Personalization is a pervasive trend among many makes and models of consumer products. Apple launched one such trend when it unleashed translucent iMacs in a variety of colors that were previously omitted from the monochromatic computer case color wheel. Since then, other products such as MP3 players, external drives and even internal components have been treated to a number of fits, finishes and forms that redefine and, in essence, personalize your gear. This phenomenon goes beyond the equipment's exterior appearance - even graphical display interfaces are endowed with the ability to uniquely theme, wallpaper, and choose any color scheme you might like.
In the same way that such devices plug into our personal lives to extend their forms or functions, software components can do the same for applications we use every day. Web browsers have plug-ins and extensions (for embedded video playback or extended audio format support), as do our email clients (for spam content filtering, advanced message handling, or consolidating account management) and other programs do likewise. Though not all of them personalize our viewing or listening experience, they do make the casual PC experience more unique. In addition, some of these plug-ins also provide more cosmetic enhancements (such as a media player visualization plug-in) or properties that affect theme and color schemes for our favorite software.
Plug-in applications are modular programs that provide added functionality to larger, more complex parent applications. They usually provide features that would otherwise be missing from such an application, such as a video player embedded within a Web browsers. By the same token, the MythTV frontend may be complemented by a range of modular plug-in applications that expand upon existing frontend features to provide other useful features.
The core group of MythTV plug-ins, taken in alphabetical order, make up the headings for the rest of this section (there are 13 in all, so you'll need to keep reading for a while). Collectively, these plug-ins represent common HTPC software components taken from a purely open source context. For that reason, you are welcome to modify existing code, to implement new features and even, to create your own plug-ins from scratch.