Adding new language translations, creating your own or simply modifying what comes by default is so easy with OpenKM.
Add new language
And simply fill the data with your international language code. If you don't know which is yours, take a look here http://www.i18nguy.com/unicode/language-identifiers.html to find you language code.
Image icon should be 16x11 pixels take a look on http://www.famfamfam.com/lab/icons/silk/
Edit a language
Delete a language
|English language is the base language and can not been deleted|
Take a look here Language_Packs. There're some available translations. Simply select one and click on the "add new translation" button.
You can export the translation file and share it with other users. Take a look here Language_Packs.