From their website (where the image was taken and converted to jpg), Ardour is described as "a digital audio workstation. You can use it to record, edit and mix multi-track audio. You can produce your own CDs, mix video soundtracks, or just experiment with new ideas about music and sound."
At version 2, I am wondering why I missed this powerful app. Maybe because it runs only on Mac OS X and Linux, whilst Audacity adds Windows support.