It is possible to use TesseractGUI 0.3 to do OCR on other languages but you have to download the language pack for the required language and install it as part of the TesseractGUI application bundle.
E.g. for German:
1/ Download the German training data (e.g. http://code.google.com/p/tesseract-ocr/downloads/detail?name=deu.traineddata.gz&can=2&q=)
2/ The archive will expand into a file called deu.traineddata
3/ Copy the deu.traineddata inside the TesseractGUI application bundle, under Contents/Resources/tessdata/
4/ Configure TesseractGUI to use the language pack (Set Preferences->Custom language spec to read deu)
5/ Load a TIFF file containing a scan of something written in German.
That should be it.
E.g. for German:
1/ Download the German training data (e.g. http://code.google.com/p/tesseract-ocr/downloads/detail?name=deu.traineddata.gz&can=2&q=)
2/ The archive will expand into a file called deu.traineddata
3/ Copy the deu.traineddata inside the TesseractGUI application bundle, under Contents/Resources/tessdata/
4/ Configure TesseractGUI to use the language pack (Set Preferences->Custom language spec to read deu)
5/ Load a TIFF file containing a scan of something written in German.
That should be it.