Lis (Library of Iterative Solvers for linear systems; pronounced lis]) is a scalable parallel software library to solve discretized linear equations and eigenvalue problems that mainly arise from the numerical solution of partial differential equations using iterative methods.

Lis provides facilities for: A C program to solve the linear equation

is written as follows: Installing Lis requires a C compiler.

[4] For parallel computing environments, an OpenMP or MPI library is necessary.

Lis supports both the Matrix Market and Harwell-Boeing formats for importing and exporting user data.