TheHaloMod: An online calculator for the halo model
  The halo model is a successful framework for describing the distribution of
matter in the Universe -- from weak lensing observables to galaxy 2-point
correlation functions. We review the basic formulation of the halo model and
several of its components in the context of galaxy two-point statistics,
developing a coherent framework for its application. We use this framework to
motivate the presentation of a new Python tool for simple and efficient
calculation of halo model quantities, and their extension to galaxy statistics
via a \textit{halo occupation distribution}, called \halomod. This tool is
efficient, simple to use, comprehensive and importantly provides a great deal
of flexibility in terms of custom extensions. This Python tool is complemented
by a new web-application at https://thehalomod.app that supports the generation
of many halo model quantities directly from the browser -- useful for
educators, students, theorists and observers.
