San Le's Free Computational Electromagnetics (SLFCEM) is a package of scientific software for use in computational electromagnetics. Command-line driven calculation engines are separate from the GUI components and can be used independently. It includes two of the basic finite elements types, 4 node quad and 3 node triangle. Each element type has a unique GUI specific to the element. Modal analysis for solving the waveguide problem is done using edge based elements. There is also code for generating edge connectivity. The algorithm used is a combination of Lanczos for tridiagonalization of the system, as well as QR to calculate the resulting eigenvalues. In addition to skyline storage and LU decomposition, calculations are also made using the Conjugate Gradient Method.