Excluding Winamp, here is a comparative look at several audio player software on market today:
AllPlayer: released in 1998, this is freeware using proprietary software.
Amarok: released June 2003, this is freeware using GPL software. Written in C++.
aTunes: released in 2006, this is freeware using GPL software. Written in Java.
Audacious – released in October 2005, this is freeware using GPL software. Written in C, C++.
Audion – released in August 1999. Freeware; proprietary.
Banshee – released August 2005. Freeware using MIT software license. Written in C#.
Beep Media Player – released June 2004, freeware using GPL. Written in C.
CDPlayer – released November 1992 by Microsoft. Freeware; proprietary.
cmus – released January 2005, freeware using GPL software license. Written in C.
Cog – released May 2006; freerware using GPL software license. Written in Objective-C.
Creative Media Source – released in 2002. Part of a non-free Creative product bundle. Proprietary.
Decibel Audio Player – released May 2007. Freeware using GPL software license. Written in Python.
Exaile – released May 2006. Freeware using GPL software license. Written in Python.
Flash MP3 Player – released March 2008; freeware using proprietary software.
foobar2000 – released December 2002; freeware using proprietary software.
JuK – released February 2003; freeware using GPL software license. Written in C++.
Listen – released March 2006; freeware using GPL software license. Written in Python.
Media Jukebox – released 1998. $40USD. Uses proprietary software.
MediaMonkey Standard – released August 2003. Freeware using proprietary software.
MediaMonkey Gold – released August 2003. $19.95 USD. Proprietary software.
MediaMonkey Lifetime – released August 2003. $29.95 USD. Proprietary software.
MPXPLAY – released 1998. Freeware using GPL software license.
Music on Console – released 2002. Freeware using GPL software license. Written in C.
Music Player Daemon – released May 2003; freeware using GPL software license.
MusicBee – released December 2008; freeware using proprietary software. Written in VB.NET
Musicmatch Jukebox Basic – released in May 1998 by Yahoo. Freeware using proprietary software.
Musicmatch Jukebox Plus – released in May 1998 by Yahoo. $19.95. Uses proprietary software.
musikCube – released in 2005. Freeware using BSD software license.
Napster – released October 2003. $9.95. Uses proprietary software.
Quod Libet – released October 2004. Freeware using GPL licenses. Written in Python.
QuickPlayer – released July 2006. Freeware using GPL software license.
Rhapsody – released 2003; freeware using proprietary software.
Rhythmbox – released April 2004. Freeware using proprietary software.
SE-mediaplayer – released February 2010. Freeware using proprietary software.
Songbird – released February 2006; freeware using GPL software license. Written in C++.
UADE – statble build in August 2008. Freeware using GPL license.
XMMS – released November 1997; freeware using GPL license. Written in C.
Yahoo! Music Jukebox Basic – released in 2005; freeware using proprietary software.
Yahoo! Music Jukebox Plus – released in 2005; $19.95 using proprietary software.
Zinf – released April 2002; freeware using GPL license.