Neutrinos open a new page in multimessenger astronomy along with gravitational-wave events, the heralds of new discoveries in physics. In extragalactic astrophysics, neutrino sources add to the relatively well-studied electromagnetic objects. We have developed a program in C/Python to work with the extragalactic neutrino background. The program cuts out desired areas in the sky in equatorial or galactic coordinates, out of all objects taken from the input catalogs creates samples of potential neutrino sources falling into the given area, calculates the neutrino flux from each source via a number of model neutrino energy spectra for different types of sources, and draws 2D splines of the neutrino flux in the sky with parameterized smoothing, which are then taken as the observed extragalactic neutrino background.