o all I need is Unicode, right?

Unicode is not a magic wand; it is a standard for the storage and interchange of textual data. Somewhere there has to be code that recognizes and provides for the conventions of different languages and countries. These conventions can be quite complex, and require considerable expertise to develop code for and to produce the data formats. Changing conditions and new markets also require considerable maintenance and development. Usually this support is provided in the operating system, or with a set of code libraries.