QSO Absorption Lines: The UV Rest-Frame from 0 < z < 4

By charting the kinematic, chemical, and ionization conditions of galactic and intergalactic gas over the redshift range 0 - 4 with QSO absorption lines, the evolution of chemical abundances, the UV meta-galactic background, and the clustering dynamics of galactic gas can be studied. HIRES/Keck Mg II 2796 profiles arising in = 1 galaxies are presented and the Mg II kinematic clustering function is given. The intriguing z = 0.93 systems toward Q1206+459 are shown and compared to z = 2 HIRES/Keck C IV profiles to illustrate how STIS/HST can be exploited for studies of the high ionization conditions in z < 1 Mg II selected systems. The scientific motives and plans for a large Mg II survey for 2 < z < 4 in the Near IR using the new 10-meter Hobby-Eberly Telescope are presented.