To solve a Poisson equation, I am currently using code which uses the Hypre library with MPI. I would like to know what else is out there, and if there is some accepted standard in the industry, i.e. what do most people use?
The library must be able to work for 2D and 3D cases, relatively easy to incorporate into an existing code and MPI compatible. It should work either with Fortran (preferred) or C++/C.