Forum OpenACS Q&A: Response to How to use double index.adp?

I suspect you will have to learn some more TCL :) If you let them set their language (with a cookie or something) like this

set lang en
ad_return_template "index_$lang"

you could get the language form the accept-language header sent by the browser. Here is a bad hacky example of that:

set lang [lindex [split [ns_set iget [ns_conn headers] accept-language] "-,;"] 0]