XNS solves for the axisymmetric equilibrium configuration of neutron stars in general relativity. It can model differentially rotating and magnetic fields that are either purely toroidal, purely poloidal or in the mixed twisted torus configuration. Einsten's equations are solved using the XCFC approximation for the metric in spherical coordinates.
http://adsabs.harvard.edu/abs/2011A&A...528A.101B and http://adsabs.harvard.edu/abs/2014MNRAS.439.3541P