XnView Software

It should be good to set IPTC tags to UTF8.

Some help for it:
http://cpanforum.com/threads/2114
Yes, you can write UTF-8 to IPTC using ExifTool. If you do this, you are responsible for setting the value the CodedCharacterSet tag to "ESC % G", this is not done automatically. (Note: Use this exact string -- ExifTool translates to the proper byte sequence for the escape code.)

http://www.sno.phy.queensu.ca/~phil/exi ... /IPTC.html
90 CodedCharacterSet string[0,32]! (values are entered in the form "ESC X Y[, ...]". The escape sequence for UTF-8 character coding is "ESC % G", but this is displayed as "UTF8" for convenience. Either string may be used when writing. The value of this tag affects the decoding of string values in the Application and NewsPhoto records.
This tag is marked as "unsafe" to prevent it from being copied by default in a group operation because existing tags in the destination image may use a different encoding. When creating a new IPTC record from scratch, it is suggested that this be set to "UTF8" if special characters are a possibility)

There is no technical problem, i read IPTC utf8 already....

Thanks for XnViewMP.
I found only two freeware programs which work with IPTC and XMP way, which is nice usefull: XnViewMP and Zoner Photo Studio.

I have images containing IPTC strings encoded with UTF-8, containing accented characters which are outside the Latin-1 range. XnView 1.97.7 displays these characters without accents. Although this is better than displaying them as incorrect ASCII characters, XnView should really display them according to the UTF-8 encoding. The Envelope.CharacterSet tag (0x005a) is set in the images with the correct code to indicate UTF-8.

Please check XnViewMP 0.30