The most important factor deciding the fate of a star and its surroundings is its initial mass.  The relative number of high- and low-mass stars decides how much light and mass escape from a population of stars.  This distribution, the stellar initial mass function, is often assumed to be universally invariant, though we have plenty of reason to believe it varies with environment.  I will present results from and previews of several ALMA programs that measure the mass distribution of pre- and proto-stellar objects at early phases, particularly the ALMA-IMF and ACES Large Programs.  Core mass function measurements suggest that more intensely star-forming regions preferentially form high-mass stars.  On larger scales, the degree of clustering varies with environment: more stars form in clusters in the Galaxy's Central Molecular Zone
than in the Galactic disk.  Measuring these environmental effects in the Galaxy, where we can resolve the individual stars but still recover the larger environment, gives us a firm footing on which to base star formation theories.
However, measurements of pre- and proto-stellar mass remain challenging, so throughout this talk, I will emphasize techniques we are developing and using to improve mass measurements at early stages of star formation, including kinematic measurements using brinary disks.

Breve CV del Prof. Dr. Adam Ginsburg:

Prof. Adam Ginsburg is an Assistant Professor at the University of Florida.  He received his PhD from the University of Colorado, after which he was an ESO fellow and then a Jansky fellow.  His group studies high-mass star formation  observationally, using ALMA, VLA, JWST, GBT, and GTC data.
(for more detail, see my CV on my website)