This script is intended for use only on ProjectEuler.net and it was build to be used together with Firefox's GreaseMonkey extension.
Repository is hosted here: https://github.com/SoboLAN/projecteuler-translation-script
It places 5 flags (British, Romanian, Russian, Korean and German) on top of every problem's page. By clicking on the flag, the corresponding translation of a problem is retrieved.
Obviously, not at all problems are available in the above mentioned languages. In this case, clicking on the flag will do nothing.
Notes about implementation:
The translations are parsed from the corresponding translations websites:
You can see a demo on how the script works in the video on this page: http://projecteuler.radumurzea.net/greasemonkey.php