GImageView is a GTK+ based image viewer. It supports tabbed browsing, thumbnail table views, directory tree views, drag and drop, reading the thumbnail cache of other famous image viewers, and a flexible user interface. It also support movies using the Xine library and MPlayer, and supports images in compressed archive formats like tar.gz, zip, and lha.
MaGnuX MP3 Control Server is a server that allows you to control the playing of MP3 songs. It uses mpg123 to play the songs, and features playlist management, a builtin Web server, IP-based access control, and much more. It's written entirely in Ruby, which makes it extremely flexible and very easy to extended.