High-performance Unicode and Punycode processing for internationalized domain names. The puny_encode() / puny_decode() helpers are a low-level, RFC 3492 compliant Punycode codec for domain labels (the xn-- ASCII-Compatible Encoding of RFC 5890/5891); they perform the raw transform plus letter-digit-hyphen checks and do not apply Unicode IDNA normalization. host_normalize() is the Unicode Technical Standard #46 host-normalization entry point, mapping a host name to a canonical lowercase ASCII comparison form (non-transitional profile, pinned Unicode version). The url_encode() / url_decode() / parse_url() helpers do best-effort host extraction and rewriting in URL-shaped strings and are deliberately not RFC 3986 / WHATWG URL parsers or canonicalizers; they are deprecated in favor of dedicated URL packages. Aimed at host normalization and data analysis workflows. Used as the Punycode and IDNA engine by the pslr and rurl packages.