When I said that we used something in the past, I was referring to this L10ns automation for translation strings. It's good enough for a medium project, but maybe gets too bloated when you have a large number of strings or in several languages ..
L10ns works by scanning your files, collecting the string ids of your texts, and coming up with a list of them to be translated into different languages. With some external help like poEditor, or it's built-in web interface, you can keep up with translations for your site.
Any other input guys??