20 Years of SpeX Spectroscopy: A Spectral Library of Diverse Stellar Sources

Stellar spectral libraries, from the Henry Draper catalog to today's large-scale optical and infrared surveys, have long served a central role in advancing our understanding of the Universe, from the characterization of diverse Milky Way populations to the discovery of rare or transient sources. In addition to dedicated spectral surveys, millions of spectra are also present in observatory archives, many of which remain unpublished and unavailable for scientific analysis. Here, we present a collaborative effort to reduce, analyze, and disseminate over 20 years of near-infrared spectral data now available through the IRSA SpeX Archive and IRTF Legacy Archive. We summarize the contents of these archives by source type; review the status of our current reduction efforts, including the development of a python-based version of the popular Spextool package; describe tools developed in this program for data visualization and analysis; and highlight potential science opportunities, including spectral variability studies, machine-learning classification algorithms, and exoplanet host star characterization, all relevant to forthcoming infrared spectral surveys conducted with JWST, SPHEREx, Euclid, and the Nancy Grace Roman Space Telescope. Data will be made publicly available in multiple data formats through the IRSA Data Archive.