Liberal URL-matching Regex, Take Two

(?x)
\b
(                       # Capture 1: entire matched URL
  (?:
    [\w-]+:                 # URL protocol and colon
    (?:
      /{1,3}                    # 1-3 slashes
      |                         # or
      [[:alpha:][:digit:]]      # Single letter or digit
                                # (Try not to match, say "URI::Escape")
    )
    |                       # or
    www\d?[.]               # "www.", "www1.", "www2.", etc.
  )
  (?:                       # One or more:
    [^\s()<>]+                  # Run of non-space, non-()<>
    |                           # or
    \([^\s()<>]+\)              # a matching set of parens
  )+
  (?:                       # End with:
    \([^\s()<>]+\)              # a set of parens
    |                           # or
    (?:                             
      [^[:punct:]\s]                # a non-punctuation non-space char
      |                             # or
      /                             # a slash
    )
  )
)