http://ml.imperia.org/libintl-perl/2005/08/16/6289725913ab0bbaa57235297ed06db9/ https://rt.cpan.org/Public/Bug/Display.html?id=49758 See also http://i18n.mbsandbox.org/ – anything with an em-dash declared as such (rather than using the HTML entity) doesn't work, likewise smart quotes; haven't looked further. Good example is the blurb starting "Like Wikipedia ..." on the front page, and the three links below that. Those are translated in en-aq (our testing pseudo-translation) and de, at the least, probably many other places. This is a side effect of needing to use the pure-perl gettext module (Locale::gettext_pp) – it works fine with the XS version, but that one doesn't allow the language to change per-request; it caches the first request and then uses that language from there on (we think – it may be that our way of language-switching isn't doing anything, and we should use nl_putenv and LC_ALL rather than setting $ENV{LANGUAGE} ). Clearly one thing or the other needs changing; I have no clear way to tackle the XS language-caching issue (either way it plays out), hence this.