The ML package in Trilinos provides algebraic multigrid methods based upon smoothed aggregation. ML contains algorithm variants appropriate for Poisson, elasticity, convection-diffusion, H(curl), and H(div) problems. The successor to ML is MueLu, which supports a variety of scalar types via templating, including extended precision types. Optimal algorithmic scaling in MueLu has been demonstrated on 1 million cores of Sequoia BG/Q.

Usage and applications: ML is distributed in Trilinos (> 4800 downloads/year). ML is used throughout the DOE complex in ASC applications, in Department of Defense applications, and at universities worldwide. For example, ML is used within Sandia’s Sierra engineering mechanics simulation suite.