Trilinos is a collection of open-source software libraries, called packages, intended to be used as building blocks for the development of scientific applications.

The word "Trilinos" is Greek and conveys the idea of "a string of pearls", suggesting a number of software packages linked together by a common infrastructure.

Trilinos was developed at Sandia National Laboratories from a core group of existing algorithms and utilizes the functionality of software interfaces such as BLAS, LAPACK, and MPI.

In addition, some Trilinos packages have growing support for shared-memory parallel computation.

They do so by means of the Kokkos package, which provides a common C++ interface over various parallel programming models, including OpenMP, POSIX Threads, and CUDA.