What about typesetting?
This article only covers the characters and fonts involved in outputting text written in different languages. That's a problem in multilanguage environments like the internet, but it's not the only one.
The output has to be displayed correctly as well. Western languages are written and read from left to right. Most text printing routines can only handle that way of outputting text. But it's not the only one. Arabic text goes from right to left (just the opposite of western languages). And if I remember corretly, some eastern languages are even written from top to bottom, that is, in colums rather than lines.
So you have to think about a way to handle output as well. A graphical system can print single characters correctly, but they need to be alligned correctly to form a text that makes esnes - sorry, I meant "sense".
I think that this becomes a serious problem if you build a system that is capable of printing all those characters at the same time. How do you typeset a text that contains passages in English, Arabic and Chinese?
Re: tell more
> There is not enough information about
> this os please send me some
I'd like to send you some more information, but I hate to tell you that not everything that has to be told about ChallengeOS has been written down yet and it is unlikely to be written down in the near future. However, I'll release some half-finished documents I already have on the project's web page (http://challangeos.sourceforge.net) as soon as possible. The problem with them is that some of them have already become outdated or give incorrect information. I promise that I'll try to update the documentation in this package as soon as I come to writing docs again, which won't be so soon, I'm afraid.