ASA245 is a C library which evaluates the logarithm of the gamma function, by Allan Mcleod;
ASA245 is Applied Statistics Algorithm 245. Source code for many Applied Statistics Algorithms is available through STATLIB.
The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.
ASA245 is available in a C version and a C++ version and a FORTRAN77 version and a FORTRAN90 version and a MATLAB version.
FN, a C library which approximates elementary and special functions using Chebyshev polynomials, by Wayne Fullerton.
TEST_VALUES, a C library which contains sample values for a number of distributions.
TOMS291, a C library which evaluates the logarithm of the Gamma function.
Original FORTRAN77 version by Allan Mcleod; C version by John Burkardt.
You can go up one level to the C source codes.