WMAP is distributing the following software packages:
Cosmological Parameters Plotter is a tool that shows probability plots for various parameters derived from WMAP Markov Chains. [This was not updated for the final WMAP release and has therefore been disabled.]
Likelihood Code, consisting of FORTRAN subroutines to compute the likelihood of an input theoretical power spectrum fit to the WMAP power spectra, using the correct Fisher matrix. Download Further details
Chain Analysis Software, an adaptation of the CosmoMC getdist program for analyzing WMAP5 Markov Chains. Download Further details
Skymap I/O Code, consisting of FORTRAN and IDL routines to read the the combined IQUS FITS format used in the second and later WMAP data releases. This is the software bundle released with the second data release. Download README