LensIt: CMB lensing delensing tools

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.