Haven't been here in awhile, but was stopping by to update our software listing, so figured I'd check the forums.

Most software can handle what you're looking for.  For example, our software UBB.threads at http://www.ubbcentral.com has all of the text in language files.  You can set a language encoding, for your case you'd want UTF-8, and then the language files can be translated and displayed in whatever language you want.

I'm not sure how other software handles it, but in UBB.threads when you create a language file you can specify a text direction of ltr or rtl.  So, if you have multiple languages available, one might read from right to left, while the other could read left to right.   No modifications to the software itself.