+
+% Catcode each special character valid in URL to 'other'
+\def\allowurlchars{\catcode`\#=12\catcode`\_=12\catcode`\%=12\catcode`\&=12\catcode`\$=12\catcode`\~=12\relax}
+
+% Style switches and the beginning/end of an URL
+\let\urlprefix\it
+\let\urlsuffix\/
+
+% Kern to place between "//" in an URL
+\newdimen\urlinterslashkern
+\urlinterslashkern=-0.1em
+
+% Internal macro for typesetting of URLs
+\def\displayurl#1:#2#3^^X{{\urlprefix #1:#2\ifx#2/\kern\urlinterslashkern\fi#3\urlsuffix}}