TOMS612 is a FORTRAN77 program, using double precision arithmetic, which approximates the integral of a function over a triangular region.
DUNAVANT is a FORTRAN90 library of routines for defining Dunavant rules for quadrature on a triangle.
FEKETE is a FORTRAN90 library of routines for defining a Fekete rule for quadrature or interpolation over a triangle.
INTLIB is a FORTRAN90 library of routines for numerically estimating integrals in one dimension.
MACHINE is a FORTRAN77 library of routines which store the appropriate values of machine constants for a given machine.
NINTLIB is a FORTRAN90 library of routines for numerically estimating integrals in multiple dimensions.
QUADPACK is a FORTRAN90 library of routines for estimating integrals in one dimension.
QUADRULE is a FORTRAN90 library of routines for defining quadrature rules on a variety of intervals with different weight functions.
STRI_QUAD is a FORTRAN90 library of routines which can approximate the integral of a function over the surface of a sphere.
STROUD is a FORTRAN90 library of routines for defining quadrature rules on a regions of a variety of shapes and dimensions.
TEST_NINT is a FORTRAN90 library of functions that can be used to test N-dimensional quadrature routines.
TEST_TRI_INT is a FORTRAN90 library of functions that can be used to test algorithms for quadrature over a triangle.
TOMS351 is a FORTRAN77 library which estimates an integral using Romberg integration.
TOMS379 is a FORTRAN77 library which estimates an integral.
TOMS418 is a FORTRAN77 library which estimates the integral of a function with a sine or cosine factor.
TOMS424 is a FORTRAN77 library which estimates the integral of a function using Clenshaw-Curtis quadrature.
TOMS468 is a FORTRAN77 library for the "automatic" integration of a function.
TOMS706 is a FORTRAN77 library which estimates the integral of a function over a triangulated region.
TRIANGULATION is a FORTRAN90 library of routines for triangulations, which includes some quadrature rules on triangles.
WANDZURA is a FORTRAN90 library of routines for defining Wandzura rules for quadrature on a triangle.
You can go up one level to the FORTRAN77 source codes.