Since its invention 30 years ago, hologram interferometry has grown from laboratory discoveries to full-fledged methodologies. It has not only influenced developments of this period, but has responded to them as well. From its start as a methodology based on silver halide recording materials, it has evolved through thermoplastic, photoresist, crystal, and other recording materials to fully take advantage of the computer revolution of the 1980's which, coupled with the development of solid-state video cameras, led the way to practical holography based on the silicon chip as the recording medium. Now, as new procedures for automated data acquisition and quantitative interpretation of fringe patterns are being developed, it becomes easier and easier to use the state-of-the-art interferometric techniques in nondestructive testing, metrology, and in a variety of other applications. In this paper, some of the developments in the field of hologram interferometry are reviewed as seen from the author's perspective and involvement since late 1960's, with particular emphasis on quantitative interpretation of interferograms and the evolution of hybrid, experimental- computational, solution methodologies. This review is illustrated with representative applications from the studies of macro and micro-scale structures. As we celebrate the first 30 years of the activity in the field of hologram interferometry, I would like to dedicate this paper to all the known and unknown inventors, coinventors, scientists, researchers, workers, students, enthusiasts, and others who have contributed to its development. Also, I would like to take this opportunity to congratulate SPIE on its 40th Birthday and wish many long lasting... 'holographic'... achievements in the years to come, as we approach the year 2000 and beyond.