The main tool I use to compose and produce at the present is still Ableton Live(presently version 7). It took me some time to get my head around it, and it is by no means perfect, but it is the best tool for the way my brain works. It turns out, just incidentally, that it is a wildly successful program with amateurs and professionals alike, but I was on board at version 1.5 and knew very quickly that it would supplant all my MIDI sequencing equipment and outboard hardware sound modules.
But I thought it might be interesting (if to no one besides myself) to go back in history to recount the hardware and software tools I used for all the previous releases.