Wrong UTF-8 encoders still around?

I'm hoping to get some advice from people with experience with various
Unicode/transcoding libraries.

RFC 3987 (the current IRI spec) has the following text:

    Note: Some older software transcoding to UTF-8 may produce illegal
       output for some input, in particular for characters outside the
       BMP (Basic Multilingual Plane). As an example, for the IRI with
       non-BMP characters (in XML Notation):
       "http://example.com/𐌀𐌁&#x10302";
       which contains the first three letters of the Old Italic alphabet,
       the correct conversion to a URI is
       "http://example.com/%F0%90%8C%80%F0%90%8C%81%F0%90%8C%82"

We are thinking about removing this because we hope that software has
improved in the meantime, but we would like to be sure about this.

If anybody knows about software out there that still presents this
problems, please tell us.

Thanks, Martin.
Received on Thu Oct 20 2011 - 18:07:22 CDT