Halotools is a specialized python package for building and testing models of the galaxy-halo connection, and analyzing catalogs of dark matter halos. The core functionality of the package includes:
Fast generation of synthetic galaxy populations using HODs, abundance matching, and related methods
Efficient algorithms for calculating galaxy clustering, lensing, z-space distortions, and other astronomical statistics
A modular, object-oriented framework for designing your own galaxy evolution model
End-to-end support for reducing halo catalogs and caching them as fast-loading hdf5 files
For more information about the scope of the package, see Halotools Science Overview. The source code is publicly available at https://github.com/astropy/halotools.