An LED light fixture includes a housing forming a chamber enclosing at least one drive and an extruded portion extending therefrom. In some embodiments, the housing has a dimension in the extruded direction no less than one-third of the fixture length, and the sides of the extruded portion and of the housing have substantially congruent profiles such that enclosure and heat-dissipation functions of the fixture are facilitated without substantial discontinuity in fixture configuration therealong viewed from positions below. A plurality of substantially rectangular LED-array modules are mounted to the LED-adjacent surface which has length and width dimensions accommodating multiple modules of predetermined width and lengths.