AmpJuke makes it possible to manage and stream your music online to several clients connected through a LAN or the Internet. In addition to streaming music, it can fetch "metadata" (album covers, images, lyrics, and track "fingerprints") automatically using various Web services such as last.fm and the.echonest. You can scan and import tags from as many tracks as you like, use favorites, and customize personal settings. Its focus is on easy navigation as well as speed.
ifpgui is a Linux GUI for the iRiver iFP flash portable player. It is similar to the iRiver Manager for Windows and supports upload, download, delete, rename, device status (battery status, etc.), tuner, and playlist uploads. It supports the iFP-100, iFP-300, iFP-500, iFP-700, iFP-800, iFP-900, and possibly the N10 series. It uses a pure Qt programming interface.
Aqualung is an advanced music player originally targeted at the GNU/Linux operating system, and also running on FreeBSD, OpenBSD, and Microsoft Windows. It plays audio CDs, Internet radio streams, and podcasts as well as sound files in just about any audio format, and has the feature of inserting no gaps between adjacent tracks.