Please recommend: free recording software on Mac

[Martin Naef]

Bar,

I want to record a classical concert in 10 days on site. I just need a 
basic stereo recording at high quality. In the past, I had access to an 
Edirol R4 recorder, but these days I'm out of anything truly portable, 
and I don't want to invest into an audio interface for the PC laptop for 
just this one gig.

So the current plan is to use my TC Goldchannel as Mic-Preamp and A/D 
converter and feed its S/PDIF optical output to a recent Apple laptop 
that has an optical digital input (I can borrow it from a friend for the 
day). I think the hardware side should be sorted that way.

So what I need is a RELIABLE piece of software to record the digital 
output in 48kHz/24bit. It needs to run straight for about 1.5h, or 
probably two parts of 45 minutes each. All I need is a proper WAV or 
AIFF file at the end that I can later edit on my tried and trusted 
system. What software should I use that's painless to install, easy to 
use (I won't have to time to actually learn the thing), keeps the 24 
bits intact, doesn't choke on a long continuous recording session and is 
free?

Martin