This checker performs various tests on a Web Page to determine its level of internationalisation-friendliness. It also lists key internationalization settings related to character encoding, language declarations, text direction and class/id names. This information includes HTTP headers, which can be particularly useful for troubleshooting problems.
The checker is still only a prototype, so there are guaranteed to be bugs and missing features. It will slowly improve over the coming months, but it has been made available for use now since it is likely to be helpful to many people already.