TOMS706 is a FORTRAN77 library which approximates the integral of a function over a triangulated region.
TOMS706 is available in a FORTRAN77 version.
DUNAVANT, a FORTRAN90 library which defines a Dunavant rule for quadrature over a triangle.
FEKETE, a FORTRAN90 library which defines a Fekete rule for quadrature or interpolation over a triangle.
MACHINE, a FORTRAN77 library which stores the appropriate values of machine constants for a given machine.
STROUD, a FORTRAN90 library which defines quadrature rules on a regions of a variety of shapes and dimensions.
TEST_TRI_INT, a FORTRAN90 library which can be used to test algorithms for quadrature over a triangle.
TOMS612, a FORTRAN77 library which estimates the integral of a function over a triangle.
TRIANGULATION, a FORTRAN90 library which carries out triangulations and includes some quadrature rules on triangles.
WANDZURA, a FORTRAN90 library which defines Wandzura rules for quadrature on a triangle.
TOMS706_PRB1 is a simple example which integrates exp(x^2+y^2) over a single triangle.
TOMS706_PRB2 is an example which integrates many functions over a triangulated region.
You can go up one level to the FORTRAN77 source codes.