Patch exists in 0004168, but it also sorts languages which has been discussed as an undesirable feature at runtime.

The patch of 0004168 is already applied, so if the language names should really be localized this requires an extension. I would propose to add a new constant "s_language_localized" to the language files and use this to display the language name in the account configuration page:

$s_language_localized = 'Deutsch';

I do not think that translators of Mantis should have to worry about translating language names that are readily available elsewhere. If we were to support native language names, we should consider using the data from Unicode's CLDR (Common Locale Data Repository) and convert that to a usable format. An example is the extension CLDR for MediaWiki (http://svn.wikimedia.org/svnroot/mediawiki/trunk/extensions/cldr/)

I think we need to find a way to get rid of our ugly language string language names ('english', 'dutch', etc.) in the UI and add the native language name there, possibly prefixed or postfixed with a language code.