Xine has quite a large following, and for good reason, as it is a very capable DVD player. In addition, like most of the players reviewed here, Xine is capable of playing a large range of file types in addition to unencrypted-DVD playback. Xine easily can be extended with additional functionality as it supports plugins that enable you to incorporate new codecs (open- or closed-source) or any additional function easily. There are many plugins available for Xine on the Net ready to be downloaded.
Xine only supports the playback of unencrypted DVD directly, but support for encrypted DVDs is provided by a third-party plugin (xine_d4d_plugin). It is unlikely that Xine will support encrypted DVDs directly. The legal status of this plugin is, as always, debatable, but it is easy enough to find and install. There are some useful links on the Xine web site, and a search at Google should find the required links for this plugin. It is stated on the Xine web site that encrypted DVD playback is not going to be supported directly because of the legal issues that surround this area. However, once you have installed the plugin, Xine's playback of encrypted DVDs is smooth with no noticeable problems with audio synchronization or any video glitches.
Xine's interface is tidy and provides most of the function you might require. Depending upon your preferences, you may find that it takes up too much space on your desktop. As Xine is currently not skinnable, there is no way to change the size or layout of the GUI. If you are running XFree86 4.x, with a supported video card, you can switch Xine from windowed to full-screen mode and back again smoothly. If this is not supported by your video card or version of X, Xine still can be viewed in a window, which is the default startup mode.
Unfortunately, Xine does not support DVD menus directly; however, there is a plugin called dvdnav (available from prdownloads.sourceforge.net/dvd) that adds this functionality to Xine. This plugin is a must-have if you intend to use Xine for DVD playback. The plugin works very well, even with the complex animated menus that some DVDs have, and although this is not required for DVD playback, it obviously gives you complete access to all the features available. The code for the DVD navigation was written referencing the original Ogle DVD menu code base.