.... should be available within XC5 business by default, but it isn't yet (as far as we can see)

This previous post provides one solution:
https://forum.x-cart.com/showthread.php?t=74512 but it's quite longwinded, potentially costly and many languages would be missing anyway.
We've already said that we are not big fans of google

but having said that, this is pretty simple (and free) and would potentially help many store owners:
https://translate.google.com/manager/website/ if it does actually work correctly on XC5. Have any XC5 store owners successfully used it yet? It's not pretty

and Google are famous for some occasional '...translation issues' but it's still much better than zero translation for anybody who needs it