toms446, a FORTRAN77 code which implements ACM toms algorithm 446, for the manipulation of Chebyshev series, by Roger Broucke.
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 GNU LGPL license.
toms446 is available in a C version and a C++ version and a Fortran90 version and a MATLAB version and an Octave version.
bernstein_polynomial, a FORTRAN77 library which evaluates the Bernstein polynomials, useful for uniform approximation of functions;
chebyshev_series, a FORTRAN77 library which can evaluate a Chebyshev series approximating a function f(x), while efficiently computing one, two or three derivatives of the series, which approximate f'(x), f''(x), and f'''(x), by Manfred Zimmer.
DIVDIF, a FORTRAN77 library which computes interpolants by divided differences.
Original FORTRAN77 version by Roger Broucke; This FORTRAN77 version by John Burkardt.