Audacity is a free, easy-to-use audio editor and recorder for Windows, Mac OS X, GNU/Linux, and other operating systems.

Audacity allows you to open audio files, import audio from the line-in of your sound card or copy audio from CDs. It has an easy to use interface and you can see the wave structure of the audio file along a timeline. You can then make clips, cut, copy and paste clips along the timeline. You run some basic filters and effects like normalize volume levels across a selection or an entire file, fade regions of the file in, out or across, pan the sound from left to right or vice versa, and many more...

Additional infomation: You'll need the Lame Lib encoder to export to MP3. Mac | Windows

Max is an application for creating high-quality audio files in various formats, from CDs or files.

Once the audio is extracted, Max allows you to save the audio in over 20 compressed and uncompressed formats including MP3, Ogg Vorbis, FLAC, AAC, Apple Lossless, Monkey's Audio, WavPack, Speex, AIFF, and WAVE. If you would like to convert your audio from one format to another, Max can read and write audio files in over 20 compressed and uncompressed formats at almost all sample rates and sample sizes. For many popular formats the artist and album metadata is transferred seamlessly between the old and new files.

MediaCoder is a free universal audio/video batch transcoder, putting together lots of excellent audio/video codecs and tools from the open source community into an all-in-one solution, capable of transcoding among different audio/video formats with many extra features. From the Mediacoder interface, you simply choose the file you wish to encode. Mediacoder then automatically displays the current setting of the file including its current format and the codec used in this format. You can then choose from a variety of output formats, specify the desired output format and run the encoder.