Polyglot is a collaborative effort to provide translations of common gaming terms (such as Save, New Game, Settings, You Won!, Inventory Full...) into all 25 languages Steam supports plus a few others.

Some of them (such as Arabic, which isn't supported by Steam, but still there) have a long way to go. Others are "100%", but it couldn't hurt to have native speakers proof-read them.

So check it out! Help if you can. And maybe it'll be of use to you!