Trilinos, which is originally a Greek term that translates to “a string of pearls”, is a collection of libraries for ESC. The translation is meant to signify that each package is a pearl in its own right (in the sense of a beautiful building block) but that the packages are also connected by a common infrastructure (the string). The Trilinos project contains over 50 independent packages, each aimed at solving a primary class of scientific computing problem. At the core of Trilinos packages are parallel solver algorithms designed to solve large-scale, complex multi-physics applications from science and engineering.