TOMS563 is a FORTRAN77 library which solves a linearly constrained L1 optimization problem.
TOMS563 is ACM TOMS Algorithm 563. The text of the original FORTRAN77 version is available online through ACM: http://www.acm.org/pubs/calgo or NETLIB: http://www.netlib.org/toms/index.html.
Richard Bartels, Andrew Conn.
You can go up one level to the FORTRAN77 source codes.