  Gas-filled Time Projection Chambers (TPCs) with Gas Electron Multipliers
(GEMs) and pixels appear suitable for direction-sensitive WIMP dark matter
searches. We present the background and motivation for our work on this
technology, past and ongoing prototype work, and a development path towards an
affordable, 1-$\rm m^3$-scale directional dark matter detector, \dcube. Such a
detector may be particularly suitable for low-mass WIMP searches, and perhaps
sufficiently sensitive to clearly determine whether the signals seen by DAMA,
CoGeNT, and CRESST-II are due to low-mass WIMPs or background.
