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 default Unicode version, selectable per call from the set the build ships). Aimed at host normalization and data analysis workflows. Used as the Punycode and IDNA engine by the pslr and rurl packages.