Of late,
Audacity http://audacity.sourceforge.net/ has changed from being my principle open-source audio application to the "fast and loose" option, great for audio file conversion and editing, and the ideal vehicle for the
Lame codecs http://lame.sourceforge.net/index.php .
The fact that it is not an entirely
JACK-compliant
http://jackaudio.org/ application makes integrating it into my current recording/editing/mixing/mastering set-up troublesome, but it is still an indispensable stand-alone tool.
Ardour http://ardour.org/ is so solid and versatile, with apparently endless capabilities. It has taken Audacity's place as my audio workstation.
And now
JAMin http://jamin.sourceforge.net/en/about.html is finally integrated as my mastering application, coupled with Ardour. It is so comforting to be able to make those subtle adjustments in EQ, compression and overall level, hear the improvement, and then have the results verified numerically and graphically. Beautiful
(the meters and graphical readout on
JAMin are so complete, I don't know if
Meterbridge http://plugin.org.uk/meterbridge/ will ever be necessary)