Web::Mention
Web::Mention is a Webmention library for the Perl programming language, developed by Jason McIntosh. It is free and open-source software, and is available through the CPAN.
Web::Mention (pronounced "Web mention" -- the colon-colon being a silent Perlish naming convention) thoroughly implements the Webmention standard, well enough to pass all the tests posed by Webmention.rocks. It can send webmentions manually, or automatically based on given HTML. It can parse and verify webmentions received via HTTP, can also extract information about a verified webmention's author and displayable content, using the respective IndieWeb algorithms for these tasks.
Its page on MetaCPAN contains more information about the library, including API documentation and usage examples.