This paper gives brief descriptions of three recent developments not so much in laser resonators themselves as in the tools for analyzing and measuring the quality of laser beams and resonators. These tools include personal computer programs for analyzing laser beams and resonators; a new method for characterizing and measuring the "beam quality" of a laser output beam; and a new "ray-pulse" method of analysis for describing beams and resonators which involve any combination of ultrashort optical pulses, broadband optical signals, and dispersive optical elements.