Syntax highlighting in BUEditor ?

Unfortunately, not possible.

Ok. Thanks for the info ;) I have one more question:
Is there any way to add a texarea parameter -> wrap = "off" (to turn off the automatic line break) ?

you may try white-space property of CSS
#TEXTAREA-ID {
white-space: nowrap;
}

So it does not work :( (see attachment)

then try overflow: scroll;

Nothing :(

sorry, can't help.

I found this syntax highlighter: http://marijn.haverbeke.nl/codemirror/
Here is XML/HTML example: http://marijn.haverbeke.nl/codemirror/htmltest.html

Would be possible to implement this syntax highlighter into BuEditor ?

Those are nice syntax highlighters but integrating them into BUE requires a rewrite of all editor methods. It might be done by implementing a integration layer. The result could look nice but be slower for no doubt.