toms470, a FORTRAN77 code which implements ACM toms algorithm 470, for solving a linear system with an almost tridiagonal matrix.
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
toms470 is available in a FORTRAN77 version.