Revison 1
Functions for validating, parsing, and normalizing URIs and their parts.
If you find any errors, please leave a comment.

parseURI(str) splits a URI into its parts
parseQueryNumeric(str) splits a query string into its name/value pairs; returns a 2-D array
parseQueryAssociative(str) splits a query string into its name/value pairs; returns an associative array
parseURL(str) splits a URL (i.e., http(s) scheme URI) into its parts
normalizeURLDomain(domain) converts an obscured URL domain to a more readable one
normalizeIPv4(ip) normalizes an IPv4 address
normalizeIPv6(ip) normalizes an IPv6 address
normalizeURLPath(path) converts an obscured URL path to a more readable one
parseMailto(str) splits a mailto scheme URI into its parts
normalizeEmailAddress(str) converts an obscured email address to a more readable one; unfolds and removes comments
fixURL(str, domain) attempts to fix a URL if needed
fixHyperlink(str, domain, allowMailto) attempts to fix a hyperlink address (http(s) or mailto) if needed

For URLs, note that IPvFuture addresses are not supported.