toms577, a C code which evaluates Carlson's elliptic integral functions RC, RD, RF and RJ.
The text of many ACM TOMS algorithms is available online through ACM: https://calgo.acm.org/ or NETLIB: https://www.netlib.org/toms/index.html.
The computer code and data files made available on this web page are distributed under the MIT license
toms577 is available in a C version and a FORTRAN77 version and a FORTRAN90 version and a MATLAB version and a Python version.
ELLIPTIC_INTEGRAL, a C code which evaluates complete elliptic integrals of first, second and third kind, using Carlson's elliptic integral functions.
TEST_VALUES, a C code which supplies test values of various mathematical functions.