BookSmart is available in English, French, German, Spanish, Portuguese, Dutch and Italian at this time. However, BookSmart does support Unicode encoding standards, including High ASCII and Double Byte Character Set type fonts (say Cyrillic and Kanji respectively), which allow most written languages from around the world to be displayed correctly in the BookSmart application and in your books.
Basically, if the font is on your machine and you can get text in that font into BookSmart, then that text will render and print correctly (because we are just outlining the fonts in the PDF). We’ve successfully printed books with Japanese, Korean, Chinese, Thai, Russian and Hindi text. That said, we always recommend doing a proof book first if you are intending to order a lot more.
The one major caveat is that currently, the text engine ONLY supports text that runs Left-to-Right. If you attempt to enter text that runs Right-to-Left either by direct entry or copy and paste, such as Hebrew or Arabic, BookSmart doesn’t like it. One way around this, of course, is to create your pages with text in another program like InDesign and then import that page as a JPG or better yet a PNG into BookSmart.