CPAN: https://www.cpan.org/
libwww: https://www.linpro.no/lwp/
SSLeay: FAQ: https://psych.psy.uq.oz.au/~ftp/Crypto/
Download: FTP://ftp.psy.uq.oz.au/pub/Crypto/SSL/
Documentation: https://www.cryptsoft.com/ssleay/doc/
HTTP: https://www.w3.org/Protocols/HTTP/HTTP2.html
https://www.ics.uci.edu/pub/ietf/http/rfc1945.html
https://www.cis.ohio-state.edu/htbin/rfc/rfc2068.html
SNPP: https://www.cis.ohio-state.edu/htbin/rfc/rfc1861.html
Other paging protocols: https://www.pcia.com/wireres/protocol/links.htm
Web-based paging gateway list: https://www.refreq.com/PagingBody.htm