Komplexity (KPLX)
Doesn’t need any additional translations since there is nothing to be translated in this addon.
These localizations for KSP and its DLC’s are available through Steam:
English 
German (Deutsch) 
Spanish (Español) 
French (Français) 
Italian (Italiano) 
Japanese(日本語) 
Brazilian Portuguese (Português Brasil) 
Russian (Русский) 
Simplified Chinese (简体中文)
Additionally Included
Mexican Spanish (Español Mexicano) 
[Korean (한국어) 
Dutch (Nederlands) 
Norwegian (Norsk) 
Polish (Polski) 
Swedish (Svenska) 
Turkish (Türk) 
Taiwanese (国语)