  We present the full public release of all data from the Illustris simulation
project. Illustris is a suite of large volume, cosmological hydrodynamical
simulations run with the moving-mesh code Arepo and including a comprehensive
set of physical models critical for following the formation and evolution of
galaxies across cosmic time. Each simulates a volume of (106.5 Mpc)^3 and
self-consistently evolves five different types of resolution elements from a
starting redshift of z=127 to the present day, z=0. These components are: dark
matter particles, gas cells, passive gas tracers, stars and stellar wind
particles, and supermassive black holes. This data release includes the
snapshots at all 136 available redshifts, halo and subhalo catalogs at each
snapshot, and two distinct merger trees. Six primary realizations of the
Illustris volume are released, including the flagship Illustris-1 run. These
include three resolution levels with the fiducial "full" baryonic physics
model, and a dark matter only analog for each. In addition, we provide four
distinct, high time resolution, smaller volume "subboxes". The total data
volume is ~265 TB, including ~800 full volume snapshots and ~30,000 subbox
snapshots. We describe the released data products as well as tools we have
developed for their analysis. All data may be directly downloaded in its native
HDF5 format. Additionally, we release a comprehensive, web-based API which
allows programmatic access to search and data processing tasks. In both cases
we provide example scripts and a getting-started guide in several languages:
currently, IDL, Python, and Matlab. This paper addresses scientific issues
relevant for the interpretation of the simulations, serves as a pointer to
published and on-line documentation of the project, describes planned future
additional data releases, and discusses technical aspects of the release.
