The Numerical Electromagnetics Code (NEC-2) is a comprehensive
package for the analysis of the electromagnetic properties of
structures. It can analyse radiating properties i.e. antenna
gain, as well as scattering properties (radar cross section)
of structures. NEC-2 was originally written in FORTRAN.

NEC2++ is an extensive rewrite of NEC-2 in C++ by Tim Molteno.
This work was helped tremendously by the work of N. Kyriazis
who ported NEC-2 to C. The new portions of code are licensed
under the GNU Public License (GPL).