Aztec solvers.
CG solver.
CG solver with cond. num. estimation.
GMRES solver.
GMRES solver with cond.num. estimation.
recursive GMRES
CG squared solver.
TFQMR solver.
BiCGStab solver.
Sparse direct LU solver.
Super LU direct solver.
Indefinite symmetric like SymmLQ.
Fixed-point iteration.