Spectroscopic surveys of stars in the Milky Way are growing rapidly in size and scope, with the ambitious goals of unravelling the Galaxy's formation and evolution, and finding out whether our galaxy fits the current paradigm of hierarchical galaxy formation driven by cold dark matter. These surveys follow target selection algorithms aimed at extracting the most information out of a coarse sampling of the stars in the Galaxy, and as result they are seriously biased. HETDEX will be the first project to change that -- obtaining low-resolution (R 750) spectra covering 350-550 nm that will render radial velocities and overall metallicity for a flux-limited sample of > 100,000 stars down to V 20 over 60 square degrees. Questions that we hope to address include: 1) the incidence of gross chemical peculiarities, 2) the metallicity distributions of the main Galactic components, and 3) the frequency of cold substructure over a range of scales. We show simulated data and explore the performances of our preliminary data analysis software.