- routines to build hierarchical matrix structures (cluster trees, block trees, low-rank matrices and block matrices),
- parallel matrix-vector and matrix-matrix product using MPI and OpenMP,
- preconditioning techniques using domain decomposition methods,
- the possibility to use Htool with any generator of coefficients (e.g., your own BEM library),
- an interface with HPDDM for iterative solvers,
- GUI and several service functions to display informations about matrix structures and timing,
- a Python interface.
Htool is written by Pierre-Henri Tournier and I, it is available on GitHub.