If you use Cappuccino, you're down to, at most, two languages: Objective-J and your server-side language. Considering that Objective-J is essentially a superset

If you use Cappuccino, you're down to, at most, two languages: Objective-J and your server-side language. Considering that Objective-J is essentially a superset of Javascript, if you're okay with Javascript as your server-side language(or if there's some Objective-J-based server-side framework I'm not aware of), you can create web applications using just one(or, if you don't count Objective-J and JS as just one language, 1.5, at most) language this very moment.