The package Stratimikos contains a unified set of Thyra-based wrappers to linear solver and preconditioner capabilities in Trilinos. The Stratimikos package is also a place where unified testing of linear solvers and preconditioners can be performed.

Teko is a package for development and implementation of block preconditioners. This includes support for manipulation and setup of block operators. Furthermore tools exist to support decomposition of a fully coupled operator. Additionally, facilities that allow the construction of approximate inverse operators using the full complement of available preconditioners and solvers are available in Teko. Finally, a small number of generic block preconditioners has been implemented in Teko, including block Jacobi, and block Gauss-Seidel. For the Navier-Stokes equation, Teko has implementations of SIMPLE, PCD and LSC. For details on these methods see Stabilization and Scalable Block Preconditioning for the Navier-Stokes Equations and the references therein.

Teuchos provides a suite of common tools for Trilinos for developers to use. These tools include BLAS/LAPACK wrappers, smart pointers, parameter lists, XML parsers, etc.

The Thyra package contains a set of interfaces and supporting code that defines basic interoperability mechanisms between different types of numerical software. The foundation of all of these interfaces are the mathematical concepts of vectors, vector spaces, and linear operators. All other interfaces and support software is built on the basic operator/vector interfaces.

TrilinosCouplings provides a location for multiple Trilinos packages to be combined for testing integrated package capabilities.

Xpetra a lightweight wrapper to both Epetra and Tpetra. The Xpetra syntax mirrors that of Tpetra. Xpetra enables algorithm developers to write to a single interface but be able to use either Epetra or Tpetra. Xpetra can also be introduced into existing code to allow for gradual migration.