  We describe a public data release of the FIRE-2 cosmological zoom-in
simulations of galaxy formation, available at
http://flathub.flatironinstitute.org/fire, from the Feedback In Realistic
Environments (FIRE) project. FIRE-2 simulations achieve parsec-scale resolution
to explicitly model the multi-phase interstellar medium while implementing
direct models for stellar evolution and feedback, including stellar winds,
core-collapse and Ia supernovae, radiation pressure, photoionization, and
photoelectric heating. We release complete snapshots from 3 suites of
simulations. The first comprises 20 simulations that zoom in on 14 Milky
Way-mass galaxies, 5 SMC/LMC-mass galaxies, and 4 lower-mass galaxies including
1 ultra-faint; we release 39 snapshots across z = 0 - 10. The second comprises
4 massive galaxies, with 19 snapshots across z = 1 - 10. Finally, a
high-redshift suite comprises 22 simulations, with 11 snapshots across z = 5 -
10. Each simulation also includes dozens of resolved lower-mass (satellite)
galaxies in its zoom-in region. Snapshots include all stored properties for all
dark matter, gas, and star particles, including 11 elemental abundances for
stars and gas, and formation times (ages) of star particles. We also release
accompanying (sub)halo catalogs, which include galaxy properties and member
star particles. For the simulations to z = 0, including all Milky Way-mass
galaxies, we release the formation coordinates and an "ex-situ" flag for all
star particles, pointers to track particles across snapshots, catalogs of
stellar streams, and multipole basis expansions for the halo mass
distributions. We describe publicly available python packages for reading and
analyzing these simulations.
