Recent progress in the development of the concept and technology of semiconductor quantum wire (QWR) lasers is reviewed. In these quasi-one-dimensional structures, optical gain is provided by charge carriers that are quantum mechanically confined in two dimensions within wire-like active regions. These devices are expected to exhibit improved laser performance, including extremely low threshold currents (in the mu A range), higher modulation bandwidth, narrower spectral linewidth, and reduced temperature sensitivity. QWR lasers would thus be particularly useful in applications involving densely packed laser arrays and monolithic integration of lasers with low-power electronics, including computer optical interconnects, optical computing, and integrated optoelectronic circuits. Approaches for fabricating these novel structures are reviewed, and recent successful demonstrations of lasing in semiconductor QWRs are described. Prospects for further progress in this area are also discussed.>