I've added several new language files for Universal Extractor since the 1.5 release, including (as of this post): Korean, Portuguese, Portuguese (Brazilian), Romanian, and Turkish. These files can be downloaded from the Universal Extractor page and added to your current copy of Universal Extractor if you'd like, and they will be included in the next release.
I'd also like to point out that all 18 (and counting!) language files have been voluntarily translated and contributed by UniExtract users that simply wanted to use the program in their native language. I'd like to send out a big thanks to all contributors for improving Universal Extractor by making it much more accessible to foreign users. Thanks!
If a translation doesn't currently exist for your own language, and you have a good understanding of English, consider contributing a translation yourself. The process itself is very straightforward; simply copy English.ini and follow the instructions at the top of the file to translate the English strings into your native language. If you're gracious enough to contribute the new language file for all other UniExtract users, I'll be happy to add your name to the list of contributors, as well as link back to your own website (if you'd like).
The only "catch" is that I'd ask you to keep the file updated as I release newer versions of Universal Extractor. These updates typically involve only minor changes or additions, and are only necessary as often as I release new versions (which, honestly, is not that often). I can only speak English myself, so I rely entirely on the generosity of UniExtract users to maintain the language files.
Thanks again to everyone that has contributed a language file to Universal Extractor.