Copyright © 1999, 2006 Gene Michael Stover. All rights reserved. Permission to copy, store, & view this document unmodified & in its entirety is granted.
One of the source code files, getopt.c, is in the public domain. I downloaded it from the TEX User's Group web site.
All other files, both source & compiled, are copyrighted by Gene Michael Stover & released under the terms of the GNU General Public License [1]. Here's a copy of the copyright notice & license agreement at the beginning of each source file:
Copyright (c) 1999, 2006 Gene Michael Stover. All rights reserved.
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
If you just want the library & headers, download the ones you want from the lib & src directories.
If you want the source code, you could download the individual files from the links (below), or you could download the ZIP archive or the bzipped cpio archive.