I guess am easy solution would be to add a language field in the table that stores the article news info and then filter results according to site laguage set by user.
As for a default function to be implemented by Boonex in the next release, I'd look at how Netlog manages languages in users' profiles.
As for a default function to be implemented by Boonex in the next release, I'd look at how Netlog manages languages in users' profiles.