  We present the full public release of all data from the TNG50, TNG100 and
TNG300 simulations of the IllustrisTNG project. IllustrisTNG is a suite of
large volume, cosmological, gravo-magnetohydrodynamical simulations run with
the moving-mesh code Arepo. TNG includes a comprehensive model for galaxy
formation physics, and each TNG simulation self-consistently solves for the
coupled evolution of dark matter, cosmic gas, luminous stars, and supermassive
blackholes from early time to the present day, z=0. Each of the flagship runs
-- TNG50, TNG100, and TNG300 -- are accompanied by lower-resolution and
dark-matter only counterparts, and we discuss scientific and numerical cautions
and caveats relevant when using TNG. Full volume snapshots are available at 100
redshifts; halo and subhalo catalogs at each snapshot and merger trees are also
released. The data volume now directly accessible online is ~1.1 PB, including
2,000 full volume snapshots and ~110,000 high time-resolution subbox snapshots.
Data access and analysis examples are available in IDL, Python, and Matlab. We
describe improvements and new functionality in the web-based API, including
on-demand visualization and analysis of galaxies and halos, exploratory
plotting of scaling relations and other relationships between galactic and halo
properties, and a new JupyterLab interface. This provides an online,
browser-based, near-native data analysis platform which supports user
computation with fully local access to TNG data, alleviating the need to
download large simulated datasets.
