toms493, a Fortran90 code which seeks the roots of a real polynomial; this is commonly called rpoly(); this is a version of ACM TOMS algorithm 493, by Michael Jenkins.
The text of many ACM TOMS algorithms is available online through ACM: https://www.acm.org/pubs/calgo or NETLIB: https://www.netlib.org/toms/index.html.
The information on this web page is distributed under the MIT license.
toms493 is available in a Fortran77 version and a Fortran0- version.
toms419, a Fortran90 code which seeks the roots of a polynomial with complex coefficients, commonly known as cpoly(); this is a version of ACM TOMS algorithm 419.
Original Fortran77 version by Michael Jenkins. This version by John Burkardt.