axionCAMB is a modified version of the publicly available code CAMB (ascl:1102.026). axionCAMB computes cosmological observables for comparison with data. This is normally the CMB power spectra (T,E,B,\phi in auto and cross power), but also includes the matter power spectrum.
https://ui.adsabs.harvard.edu/abs/2000ApJ...538..473L and https://ui.adsabs.harvard.edu/abs/2015PhRvD..91j3512H