For example, I need to deploy a wiki site in English and a non-English language. It can be assumed all pages are available in English. Some of the pages are/should be available in the other language. When a user creates/edits the one version of a page, he may or may not create/edit the version of the opposite language.

Is there some recommended settings for this?

For example, I'd like a link pointing to the opposite language version displayed on a page:

This is an English page   <LINK TO LOCAL LANGUAGE VERSION>

and

&*^&*^*(*()*)(^%^$%^%^&*^ <LINK TO ENGLISH VERSION>

Any ideas how best to achieve something like this?

Also, can I have non-ASCII char in source file names (.mdwn)?