Allan Odegaard, the developer of [TextMate](http://macromates.com), has put up a great post about the advantages of [Unicode](http://www.unicode.org/). I must say that this is mandatory reading for those who are producing text files (especially html), and still are unaware of the benefits from using Unicode.
You can read the full post [here](http://macromates.com/blog/archives/2005/09/18/handling-encodings-utf-8/).
[tags]unicode, textmate, html, text editing[/tags]
There may well be some benefits from using Unicode, but let’s not forget about the drawbacks:
http://www.schneier.com/crypto-gram-0007.html#9
Security issues are obviously a consideration to take when using Unicode, or more specifically, when implementing support for Unicode. For character representations (XML/HTML, etc) UTF-8 is the most common Unicode scheme, and during the updates of the Unicode specification there have been numerous restrictions made on implementations of this scheme. Considering the article by Schneier, one way is to restrict the size of the character sequences which are parsed, such that illegal sequences can be ignored. This is also a requirement set by the Unicode Standard.
Here are some additionally links with information related to Unicode and security aspects: