This draft states of making zone identifier common for all browsers. It is set to expire in May , 2013
A section from this states:
Due to the lack of a standard in this area, web browsers have been inconsistent in providing for ZoneIDs. Many have no support, but there are examples of ad hoc support. For example, older versions of Firefox allowed the use of a ZoneID preceded by an unescaped "%" character, but this was removed for consistency with RFC 3986. As another example, recent versions of Internet Explorer allow use of a ZoneID preceded by a "%" character escaped as "%25", still beyond the
syntax allowed by RFC 3986. This syntax extension is in fact used internally in the Windows operating system and some of its APIs.
This document implies that all browsers should recognise a ZoneID preceded by an escaped "%". In the spirit of "be liberal with what
you accept", we also recommend that URI parsers accept bare "%" signs (i.e., a "%" not followed by two valid hexadecimal characters). This
makes it easy for a user to copy and paste a string such as "fe80::a%en1" from the output of a "ping" command and have it work.
1) IE version 7 and above support link local with '%25' added
2) Firefox older version 3.x supported, later it got removed , firefox bug which states this:
3) Chrome bug:
Could not find information on Opera and Safari.