Search-sitemap is a project mainly written in Perl, it's free.
Search::Sitemap
The Sitemap Protocol allows you to inform search engine crawlers about URLs on your Web sites that are available for crawling. A Sitemap con- sists of a list of URLs and may also contain additional information about those URLs, such as when they were last modified, how frequently they change, etc.
The Search::Sitemap module allows you to create and modify sitemaps.
COPYRIGHT AND LICENCE
Copyright (C) 2005-2009 by Jason Kohles
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.