This plugin adds IDN support to WordPress. IDN (Internationalized domain name) is a domain name that contains non-ascii characters.
This plugin adds IDN support to WordPress, making it an IDNA application. An IDN is a domain name that contains non-ascii characters. This plugin enables one to set the WordPress address (URL) to an IDN. (instead of the Punycode Representation)
Examples of an IDN:
"An IDNA-enabled application is able to convert between the internationalised and ASCII representations of a domain name. It uses the ASCII form for DNS lookups but can present the internationalised form to users who presumably prefer to read and write domain names in non-ASCII scripts such as Arabic or Hiragana. Applications that do not support IDNA will not be able to handle domain names with non-ASCII characters, but will still be able to access such domains if given the (usually rather cryptic) ASCII equivalent." - IDN entry at Wikipedia
In simple terms, this plugin allows one to set their blog url to an IDN.
If you are interested in seeing what the PUNYCODE version of your IDN is, here is an online conversion tool
As an example:
Frau Müller has a blog and wants to use the IDN, http://www.müller.de Currently, she would have to set the WP blog url, (General Settings menu) to the Punycode version: xn--mller-kva.de, (which is the ascii representation of müller.de) this would allow users using a IDN aware web browser to access the site using the desired url: http://www.müller.de (and also of course, xn--mller-kva.de).
It is more convenient for Frau Müller to use the actual IDN http://www.müller.de as the WP blog url setting (General Settings menu), this plugin enables that functionality.
There are a few caveats with using this plugin, depending on what Browser, Operating System and versions used, one can get unexpected results.
Firefox >= 3.*
Firefox supports IDN's but maintains a 'whitelist' of 'safe' domains. .com, .net, .eu are not white listed for safety reasons, so IDN's on these domains will display as Punycode. see bug:
There is an new ('experimental') Firefox add-on, IDN Navbar, which will enable all (whitelisted - Punycode) domains to display as IDN's. So, if using Firefox and this plugin you (and your visitors) may want to install that addon.
Internet Explorer >= 7.*
Safari/Opera 10.* seem to display IDN's for all domain's fine. (untested)