Arista is an easy-to-use multimedia transcoder for the GNOME desktop. It focuses on the goal of transcoding media, namely the devices you wish to play the media on. It is designed for use by people who are not familiar with audio and video encoding and want an easy way to get multimedia to their devices. It supports input from DVD and V4L devices as well as regular files.
Epris is a D-Bus service and command line client to listen to music. Unlike xmms2 or mpd, it uses GStreamer and D-Bus. It supports all formats supported by GStreamer, and can play both video and audio. It supports gap-less playback thanks to playbin2. It has an extensible command line interface, a small memory footprint, automatic deactivation, and an easy D-Bus interface for other UIs.
Orc is a library and set of tools for compiling and executing very simple programs that operate on arrays of data. The "language" is a generic assembly language that represents many of the features available in SIMD architectures, including saturated addition and subtraction, and many arithmetic operations.
Voody Blue Subtitler is a suit of programs that allows you to manually synchronize a text file with a video stream, thus creating a subtitles file. It consists of a master client (to do the sync), a slave client (projector), a relay server, and a configuration utility. It runs on Linux and Windows (all except the relay server), supports video output via GStreamer (Linux and Windows) and MPlayer (on Linux only), and supports GTK+ 2 and 3 (decided at compile time).
Peyote is an audio player with a friendly MC-like interface. It is designed specifically to work easily with cue sheets. It plays wv (wavepack), WAV, FLAC, APE, Ogg, WMA, and MP3 formats. It supports ID3v2, APEv2, FLAC, and Vorbis tags; multiple playlists; and tabs. It can copy, move, remove, and rename files.
Pimp is a highly interactive and programmable music player. It can be controlled with an mpd client or via a Python interpreter. Files can be played directly, and file paths are recorded in a database. Files are identified by a "fingerprint" which allows the user to identify an audio file despite file moving and tag modification. Pimp aims to be a player framework with a really small core. All features are implemented in extensions. For example, a lot of player events such as play, seek, and pause are logged in the database.