My tools of choice:

Platform: Windows 7, ASUS A53E i7 2630QM, on-chip Intel HD 3000 GPU
Language/libraries: Java with libgdx.
Editor: Eclipse
Version Control: Git
Graphics: Gimp, Corel Painter, Inkscape
Music: Sibelius, Epiphone Dot Semi-Acoustic Guitar, Korg X50 Synthesizer
Sound Effects: Amateur folio with built-in laptop mic and Audacity.
Organizing: Emacs Org-mode or just a *scratch* buffer
Focusing: Panic.