After LD30 and the last miniLD, I’m in for this one.
What I use:

• IDE: AptanaStudio3
• Frameworks: createjs, garfunkeljs (my own small 2d toolbox which hopefully will grow during LD)
• Sound: Sunvox, Audacity, or maybe the good old hsctracker (download)
• Graphics: GIMP, Inkscape, Epson Scanner, maybe some potatos