Ardour
Ardour is a digital audio workstation. You can use it to record, edit and mix multi-track audio.
http://www.ardour.org/
Digitale Audio-Workstation: Ardour 3.0 ist fertig
http://www.heise.de/open/meldung/Digitale-Audio-Workstation-Ardour-3-0-ist-fertig-1820210.html
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Audacity
Free Audacity sound editor
http://audacity.sourceforge.net/
Audacity-Supportforum
Audacity ist ein kostenloser Mehrspur-Audio-Editor fuer Linux, Mac und Windows
http://audacity.fuchsi.de/
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LMMS (Linux MultiMedia Studio) is a free cross-platform music studio which allows you to produce music with your computer. This includes the creation of melodies and beats, the synthesis and mixing of sounds, and arranging of samples. ...
http://lmms.sourceforge.net/
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ALSA
The Advanced Linux Sound Architecture
http://www.alsa-project.org/
Ubuntu Studio is a multimedia editing/creation flavor of Ubuntu. It's built for the GNU/Linux audio, video, and graphic enthusiast or professional.
http://ubuntustudio.org/ | https://wiki.ubuntu.com/UbuntuStudio
LAD
Linux Audio Developers Mailing List
http://www.linuxdj.com/audio/lad/
audio4linux
Musik machen mit offenen Quellen
http://www.audio4linux.de/
AGNULA
completely devoted to professional and consumer audio applications and multimedia development.
http://www.agnula.org/
MikMod
Mikmod is a module player and library supporting many formats, including mod, s3m, it, and xm...
http://mikmod.raphnet.net/
The Linux MP3-HOWTO
By Phil Kerr
http://www.faqs.org/docs/Linux-HOWTO/MP3-HOWTO.html
LinuxSampler
open source pure software audio sampler with professional grade features...
http://www.linuxsampler.org/
Linux MP3 Players Project Page
Homebrew MP3 Projects
http://www.ccs.neu.edu/home/bchafy/mp3.html
m-dist
a small, embedded Linux system tuned for MIDI and audio use.
http://www.plus24.com/m-dist/
Linux Vst Compatibility
this site is geared mainly towards compatibility information.
http://ladspavst.linuxaudio.org/
Linux-Sound Application Index
Collecting resources for the Linux-Sound community from newbie to old-hat developer...
http://apps.linuxaudio.org/
Sound & MIDI Software For Linux
Linklist
http://www.linux-sound.org/
ReZound aims to be a stable, open source, and graphical audio file editor primarily for but not limited to the Linux operating system. ...
http://rezound.sourceforge.net/
TiMidity++ is a software synthesizer. It can play MIDI files by converting them into PCM waveform data; give it a MIDI data along with digital instrument data files, then it synthesizes them in real-time, and plays. It can not only play sounds, but also can save the generated waveforms into hard disks as various audio file formats.
TiMidity++ is a free software, distributed under the terms of GNU general public license.
http://timidity.sourceforge.net/