I don't quite get what you want? ;-)
Pier and Seaside support multiple languages in a single page, see for
example the comments in this post:
<http://www.lukas-renggli.ch/blog/studenckifestwal>, so the text you
enter can be any language you want.
Pier does not have a user interface adapted to multiple languages. It
is all in english.
Cheers,
Lukas
--
Lukas Renggli
http://www.lukas-renggli.ch