Since the major review by Scalo (1986), significant progress has been achieved in constraining the mass function (MF) of low-mass stars. The break-throughs which today allow a much better understanding of the stellar luminosity function (LF) and the underlying MF are documented here and the resulting MF for Galactic field stars is confronted with microlensing data, the chemical enrichment history of the Galaxy, the Oort limit and well-studied open clusters.

15 pages incl. 4 figures (LaTeX, style files included); The figures are larger than in the 12 page review that is to appear in PASPC: Brown Dwarfs and Extrasolar Planets, R. Rebolo, M.R. Zapatero Osorio and E. Martin (eds.); International workshop held on Tenerife Island, March 17 -- 21, 1997