Hardware
K7 850Mhz
128 MB RAM
40+ GB HD
Santa Cruz SoundCard

Software
AudioMulch - An Interactive Music Studio
Fruity Tracks - Track layer. They also make a nice WAV/loop editor
MP Tracker
ACID - loop based production tool
Cool Edit Pro - digital audio recording, mixing, and editing. At a price.
Turang - there is a free version and FAT version. I am currently using the free version for quick sequences
Leaf Drums - pretty cool little drum machine, and I occasionally use it for FX and sequences
Buzz - a decent synth, but i takes a while to get used too
ALF - fantastic FREE mp3 encoder