I exported strings from Terraria so i can translate it to Czech language. Main branch should include official Terrraia strings. Translated files will be in branch named Czech. I can add more branches for different languages or you can fork it and do it yourselves.
We will translate files like this. From this:
"Key": {
"UP": "UP",
"DOWN": "DOWN"
To this:
"Key": {
"UP": "NAHORU",
"DOWN": "DOLŮ"
Files extracted from terraria with: Localization Packer. Here is official guide to make language pack: Guide