In its simplest applications FEM2DLib requires only a problem definition file (mesh, material functions etc) and about 10 lines of Fortran code. Experienced Fortran programmers can solve complex 2D problems which may involve time-dependent boundary conditions, time-dependent mesh structures, or changing mesh resolutions over advected features.
FEM2DLib can solve transient and steady state advection-diffusion problems. The library contains several types of elements (1D elements, triangular elements, directly integrated or isoparametrical with up to 9 nodes and rectangular serendipity and lagrange elements, with up to 9 nodes). The data structures are allocated dynamically, so the limit to the size of a mesh is imposed only by the amount of virtual memory available.
FEM2DLib is free for academic and non-profit uses.