plancklens contains most of Planck 2018 CMB lensing pipeline and makes it possible to reproduce the published map and band-powers. Some numerical parts are written in Fortran, and portions of it (structure and code) have been directly adapted from pre-existing work by Duncan Hanson. The lensed CMB skies is produced by the stand-alone package lenspyx (ascl:2010.010).

lenspyx creates curved-sky python lensed CMB maps simulations; the software allows those familiar with healpy (ascl:2008.022) to build very easily lensed CMB simulations. Parallelization is done with openmp. The numerical cost is approximately that of an high-res harmonic transform. lenspyx provides two methods to build a simulation; one method computes a deflected spin-0 healpix map from its alm and deflection field alm, and the other computes a deflected spin-weight Healpix map from its gradient and curl modes and deflection field alm. lenspyx can be used in conjunction with the Planck 2018 CMB lensing pipeline plancklens (ascl:2010.009) to reproduce the published map and band-powers.

LensIt enables CMB lensing and CMB delensing using the flat-sky approximation. The package can find the maximum posterior estimation of CMB lensing deflection maps from temperature and/or polarization maps and perform Wiener filtering of masked CMB data and allow for inhomogenous noise, including lensing deflections, using a multigrid preconditioner. It contains fast and accurate simulation libraries for lensed CMB skies, and standard quadratic estimator lensing reconstruction tools. LensIt also includes CMB internal delensing tools, including internal delensing biases calculation for temperature and/or polarization maps.

lensitbiases is an rFFT-based N1 lensing bias calculation and tests. It is tuned for TT, P-only or MV (GMV) like quadratic estimators. It performs rFFT-based N1 and N1 matrix calculations in ~ O(ms) time per lensing multipole for Planck-like config, which allows on-the-fly evaluation of the bias. It also calculates 5 rFFT's of moderate size per L for N1 TT, 20 for PP, and 45 for MV or GMV. lensitbiases is not particularly efficient for low lensing L's, since in this case one must use large boxes.