MythTV can be extended with plugins. MythArchive, MythGallery, MythMusic, MythVideo and MythWeb are the main ones that appear on the homepage of the application.
MythArchive enables you to make CD/DVD archives of your recordings. You can do pretty much everything with your archives: you can insert intros, animated thumbnails, subtitles, time, description, chapter menu, etc.. You can imagine making a DVD movie of your last vacation with MythArchive with all the DVD editing features. With all these building blocks, the rest depends on your imagination.

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MythGallery, as the name implies, is the photo gallery application of MythTV. If your graphics adapter supports OpenGL extensions, then MythGallery offers more than a thumbnail listing of images; it also render your image transitions. The image on the rgiht shows some photos rendered as a cube.
MythMusic does not function only as a music player. You can do almost everything you want to do with your music. For example while you are ripping your CD’s, you can download album information from the Internet (which the MythMusic takes care of automatically) and fetch album art (usually album covers). You can arrange playlists (including importing from iTunes), save different playlists etc. MythMusic also supports visualization. Better yet, you can play your music when you are looking at your photos in MythGallery.
MythVideo is where you go to arrange your videos. You can manage your recordings, DVD rips, Flash movies, YouTube clips, video camera recordings, whatever you name from MythVideo. One of the best options is to make bookmarks on DVD/VCD’s; meaning that when you are going to bed, you can bookmark the DVD and when you wake up you can pick up the movie where you left. I find it wonderful to go to just one place to see my videos. However, I wish there were a DVD ripping feature here.