The speed of a quantum chemical calculation often depends on how efficient the used numerical libraries are. Here is a list of numerical libraries that are widely used in various scientific codes.
C Program based
FFTW
GNU Scientific Libarary
Intel MKL (includes BLAS, LAPACK, ScaLAPACK, FFT, etc)
C++ Program based
Armadillo
LAPACK++
Intel MKL
Fortran Program based
LAPACK
LINPACK
Netlib
Python Program based
NumPy
SciPy
ScientificPython
SymPy
C Program based
FFTW
GNU Scientific Libarary
Intel MKL (includes BLAS, LAPACK, ScaLAPACK, FFT, etc)
C++ Program based
Armadillo
LAPACK++
Intel MKL
Fortran Program based
LAPACK
LINPACK
Netlib
Python Program based
NumPy
SciPy
ScientificPython
SymPy