Audacity is a free opensource audio editing and recording software. Audacity can run on Linux, Windows and Mac OSX. Audacity can manipulate digital audio wave forms. In addition to recording sounds directly from within the program, it imports many sound file formats, including WAV, AIFF, AU, IRCAM, MP, and Ogg Vorbis.

A digital audio editor is a computer application for audio editing or digital audio manipulation. Usually, a digital audio editor allows the user to record and edit audio, mix multiple sound sources/tracks, apply simple or advanced effects or filters, playback sound, and convert different audio file formats and different sound quality levels.

Audacity's follow-up to its cult-classic audio editor, Audacity 1.3, warrants the attention of amateur and "prosumer" music editors. Audacity 1.3 adds minor (though useful) editing effects, and greases the wheels with some time-saving functionality.

I spend a lot of time looking at other people’s computers, and I see Audacity installed on a lot of them. Not many software programs deserve the adverb “versatile”, but Audacity is one of them. It is the Swiss Army knife of audio applications.

Audacity is a really popular open source audio editor used by many people to make podcasts, create ringtones, remove vocals, and pretty much anything else you want to do with sound files.

I found a useful sound effect in an online video from NASA which replaces an earlier temporary sound I used in a scene soundtrack for the Lunatics pilot, "No Children in Space." I'm going to extract the sound from the video (with VLC), cut out the sound I need, clean it up, and insert it into an existing sound mix (all with Audacity).

Audacity is a very good free and open source audio editing application for Windows, Linux and Mac OS X.
Unfortunately, due to patent restrictions, it is unable to import, export and manipulate MP3 files in the default install and this problem is usually present in the Linux version.

Audacity 1.3.10 Beta is released. Audacity is open source software for recording and editing sounds.

A nice useful application for editing tags in your audio collection is Kid3, which currently is at version 1.0 and it offers support for all the major formats like OGG Vorbis, FLAC, MP3 or MP4. The good thing about Kid3 is that it allows you to edit tags for several files at once, instead of editing one file, saving and then starting over with the next file.