BonkEnc is a CD ripper, audio encoder and converter for various formats. It can produce MP3, MP4/M4A, Ogg Vorbis, AAC, Bonk and FLAC files.

http://www.bonkenc.org

Exact Audio Copy is a so called audio grabber for audio CDs using standard CD and DVD-ROM drives. The main differences between EAC and most other audio grabbers are :
It is free (for non-commercial purposes)
It works with a technology, which reads audio CDs almost perfectly. If there are any errors that can’t be corrected, it will tell you on which time position the (possible) distortion occurred, so you could easily control it with e.g. the media player

http://www.exactaudiocopy.org

http://www.foobar2000.org

http://www.codecpackguide.com/klmcodec.htm

http://mediainfo.sourceforge.net

MediaCoder is a free universal batch media transcoder, which nicely integrates most popular audio/video codecs and tools into an all-in-one solution. With a flexible and extendable architecture, new codecs and tools are added in constantly as well as supports for new devices. MediaCoder intends to be the swiss army knife for media transcoding in all time and at this moment, it already has millions of users from 170+ countries all over the planet.

http://mediacoder.sourceforge.net

The Music Organizer for Serious Collectors...

Manage small to very large collections of audio files and playlists (50,000+), whether on a hard drive, network, or CDs. Lookup missing information and album art online, tag almost any audio format, and automatically rename/re-organize tracks on your hard drive.

http://www.mediamonkey.com

Mp3Splt-project is a utility to split mp3 and ogg files selecting a begin and an end time position, without decoding. It's very useful to split large mp3/ogg to make smaller files or to split entire albums to obtain original tracks.

http://mp3splt.sourceforge.net

http://www.mp3tag.de

MusikCube is an mp3 player for the modern generation. Ofering you innovative features not seen elsewhere. For the technical user, musikCube is based on an embedded SQL database engine
known as sqlite. Really fast. "Dynamic playlists" allow fully automatic, randomized playback of songs based on your observed listening habits. The more you listen, the smarter it gets. It also features browsable, user reorderable playlists.

http://www.musikcube.com

Ogg Vorbis is a completely open, patent-free, professional audio encoding and streaming technology with all the benefits of Open Source.

http://www.vorbis.com

Want to listen to internet audio programs but can't when they are scheduled? This program lets you create your own custom online audio anytime, anywhere. Really.

http://juicereceiver.sourceforge.net/index.php

Songbird is a desktop media player mashed-up with the Web. Songbird is committed to playing the music you want, from the sites you want, on the devices you want, challenging the conventions of discovery, purchase, consumption and organization of music on the Internet

http://www.songbirdnest.com

Winamp 5.5 features our new Bento Skin that's easier to use and more powerful than ever. Easily access the Media Library,Playlist Editor, Video, Visualizations, Media Monitor Browser, EQ, Skin Options and Color Themes all from one single user interface.
Includes over 20 color themes that suit nearly every mood or occasion! Winamp 5.5 carries forward the unobtrusive "Window Shade" mode.

http://www.winamp.com