The ATLAS (Automatically Tuned Linear Algebra Software) project is an
ongoing research effort focusing on applying empirical techniques in
order to provide portable performance. At present, it provides C and
Fortran77 interfaces to a portably efficient BLAS implementation, as
well as a few routines from LAPACK.

The performance improvements in ATLAS are obtained largely via
compile-time optimizations and tend to be specific to a given hardware
configuration. In order to package ATLAS some compromises
are necessary so that good performance can be obtained on a variety
of hardware. This set of ATLAS binary packages is therefore not
necessarily optimal for any specific hardware configuration. However,
the source package can be used to compile customized ATLAS packages;
see the documentation for information.