toms461, a FORTRAN77 code which implements ACM toms algorithm 461, which uses cubic splines to solve a class of functional differential equations.
The text of many ACM toms algorithms is available online through ACM: http://www.acm.org/pubs/calgo or NETLIB: http://www.netlib.org/toms/index.html.
The computer code and data files described and made available on this web page are distributed under the MIT license
toms461 is available in a FORTRAN77 version.