It's actually more raw than it sounds.

I record the guitars and bass with audacity, connecting the "line out" cable on the back of my amplifier to the input on my computer and recording directly. Most people say mic'ing it is better, but honestly I don't see how. Seems like it would sound fuzzy and unclear that way.

I process all the recorded tracks with audacity as well. High pass filters, low pass filters, eq, dynamic range compression, levelling, noise removal, all that in audacity.

I make the backing tracks in midi form with Anvil Studio. Just a free midi authoring studio I found some years ago.

I use synthfont to render the midi's into .wav forms with soundfonts I found on the web to make them sound like real instruments.

Then I mix it all together with Krystal Audio Engine.

All of this software is freeware.