I have used Audacity for live recordings in my shows. But it's a one take deal & harder to manipulate for multi tracking. I have a couple older songs I did in the Showcase as well recorded live at my shows. Recording straight to a 2 track (overall mix) doesn't always reflect what you actually hear with your ears.
Krystal actually worked better for home recording in a multi-track fashion and it's free as well.
http://www.kreatives.org/kristal/
But my favorite to use that is relatively cheap was Mackie Tracktion and didn't have any latency issues.