galcv
Adam Trapp developed the galcv package for quick estimates of cosmic variance in high-redshift luminosity functions. You can download it here.
elecinterp
This simple code contains: (1) a set of data tables for the energy deposition by fast electrons in a gas of primordial composition, with the ionized fraction given by the filename, contained in the directory x_int_tables; (2) C code to interpolate these tables (across energy and ionized fraction), elec_interp.c; (3) an example application (again in C) that uses the interpolation code to compute the net deposition fractions for a power law incident spectrum and a variable minimum incident photon energy (matching Fig. 6 in Furlanetto and Stoever), xray_interp.c. You can download it here. You can read about the physics behind the code in this paper.
ARES
The Accelerated Reionization Era Simulations (ARES) code is a fast tool for rapidly modeling galaxies, radiation backgrounds, the intergalactic medium, and the spin-flip background during the Cosmic Dawn. ARES primarily focuses on computing average quantities and simple statistics. It is available publicly here. Jordan Mirocha developed and maintains the code.
21cmFAST
This is a semi-numeric simulation code for predicting galaxy populations, radiation backgrounds, and especially the spin-flip background from early times. The code produces three-dimensional realizations of the Universe during the Cosmic Dawn. It is primarily maintained by Andrei Mesinger, Steven Murray, and their collaborators, but it is available publicly and is constantly being improved. You can find the latest iteration, with a user's guide and documentation, here.
