The matrix linear algebra in the Essential Math Module class library is based on a version of the Basic Linear Algebra Subroutines (Level 1), abbreviated BLAS, which is contained in the public domain linear algebra library LAPACK. When you build the Essential Math Module, these routines are compiled into a separate library so that you may substitute your own version of the LAPACK BLAS. To do this, simply link your BLAS library into your application in place of the one that comes with the Essential Math Module.