Scripsit Ben C:

>> I don't think any browser even tries to get close to implementing
>> Unicode line breaking rules or even a simplification of them.
>
> If you're writing a browser that has to display text in a variety of
> different scripts used for languages you aren't familiar with
> yourself, it's much easier to load in the Unicode breaking class
> tables and use the Unicode specification than it is to learn all
> those scripts and their different conventions.

Quite right, so it's somewhat surprising that browsers don't do that.

One reason to this might be that Unicode line breaking rules haven't
been stable. Moreover, they are fairly complex. (And applying them
indiscriminately leads to poor results, like breaking after "-" even in
a context like "the temperature is -8 degrees".)

--
Jukka K. Korpela ("Yucca")
http://www.cs.tut.fi/~jkorpela/