Pylians: These are the set of python libraries written in c/cython/python to analyze the output of N-body and hydrodynamic simulations. They can be used to compute density fields, power spectra, bispectra, correlation functions, populate halos with galaxies, study the neutral hydrogen properties, make images/movies...etc. They are publicly available here and the documentation can be found here (github markdown) or here (html).
HADES: A very large set of more than 1000 state-of-the-art N-body and hydrodynamic simulations with massive and massless neutrinos. A description of these simulations and the methods available to download them can be found here.