XLV is a middle-level interface for Audio/Video (and generic multimedia format) playing, recording, and managing. The idea is that what you can do automatically (with one call) can also be done manually (all the decoding process can be extracted from the automate). XLV comes with a full bunch of plugins, including Vorbis, MPEG audio decoding, MPEG 1/2 video decoding, a Win32 codec interface, AVI decoder, Wave decoder, Quicktime decoder, MPEG/VOB (DVD file) decoder, and more functionalities like auto-format conversion, etc.
Elisa Media Center is a project to create a media center solution for GNU/Linux and Unix operating systems. Elisa runs on top of the GStreamer multimedia framework. In addition to personal video recorder functionality (PVR) and Music Jukebox support, Elisa also interoperates with devices following the DLNA standard, like Intel's ViiV systems.
Freepia is small GNU/Linux distribution designed to run on VIA EPIA-M mainboards. It currently only runs on the M-9000 and M-10000 (ezra and nehemia cpu) but with some modifications like kernel and X11 modules it should run on others too. The main goal of this project is to build a full-featured, low-noise media box to play movies, MP3s, images, etc. It uses freevo as its media viewer, but in the future there may be support for others, like mythtv or vdr.
PyMei is a Python media center application. It's designed to run as a full screen application on an HTPC, navigated by a keyboard or an LIRC input device. It plays videos or shows other types of media using external programs like mplayer. With its plugin support and themeability, it's aiming to be a very extensible and customizable media interface.
Lifebox is a fast, lightweight, social photo and video gallery application that is designed to organize large amounts of media. It is able to differentiate between original and modified photos so you can upload your entire library to your server and highlight your favorite photos and videos into albums to share with friends. Lifebox also makes a distinction between albums and rolls, so a single photo or video can be part of multiple albums but only one roll. It extracts data from EXIF tags and XMP sidecars, making it compatible with the data from programs like Adobe Lightroom, Picassa, and iPhoto. Lifebox is social in that people and objects can be tagged, and they will receive an email when this happens. It supports authentication, so you can control who has access to what photo.