However, it is still very useful to have an internationalization support. And then you have to use some actual framework or CMS; but this is so pointless because all you really need is just a translation support.
Please note that this is not a duplicate of questions such as this, because I could, of course, define a simple PHP file with translation array. But often you don't need to do this by yourself, but have a third person do it, so you need some simple administration area where you could edit the strings in a browser.
So please, does anyone know of a simple, file-based (ideally single file+internationalization files) PHP library with a simple login-restricted area where you can edit the strings in a browser?
I would definitely not like to reinvent the wheel :(
Note: this is a repost of this question, as it seems that that it's not ok to ask for recommendations on Stack Overflow anymore