UMFPACK

UMFPACK ( Unsymmetric Multi frontal Package) is a software library written in ANSI C for solving unsymmetric sparse linear systems using the unsymmetrical multi- frontal method. Elementary linear algebra operations are carried out by means of an implementation of the UMFPACK BLAS software library.

The license of UMFPACK has finally changed in the last two years of a BSD license to LGPL and in the latest version 5.2 to a GPL license. Some versions of the software were made ​​retrospectively under the LGPL, so that the net different licensed versions can be found. UMFPACK is, inter alia, used by MATLAB as a standard solution method for sparse matrices.