IT++ External=============IT++ External is a set of companion libraries for IT++. It provides allnecessary libraries required by IT++, i.e.:- FFTW: Fastest Fourier Transforms in the West- BLAS: NetLib's Basic Linear Algebra Sub-programs- CBLAS: NetLib's C interface to Basic Linear Algebra Sub-programs- LAPACK: NetLib's Linear Algebra Package    - ATLAS: Automatically Tuned Linear Algebra Software (optionally)Detailed instructions for configuration and installation of the IT++External be found in the INSTALL file.For increased efficiency of the IT++ library you can replace the Legacy BLASand CBLAS routines with its optimized versions. The ATLAS library can beused instead of the default legacy BLAS and CBLAS libraries. Compiling ATLAStakes much longer time and you will have to provide some input to the ATLASconfiguration script. But, if you want better performance, when using IT++,then you should try it.On several architectures you may want to use some other libraries thatprovides BLAS (CBLAS), LAPACK and FFT functionalities. Intel provides alibrary called Intel Math Kernel Library (MKL), whereas AMD has AMD CoreMath Library (ACML). Both implementation can be used with IT++.