why you should do it

• application/xhtml+xml is the correct content-type for xhtml.
• internet explorer doesn't know what to do with application/xhtml+xml
• 100webspace doesn't put their stupid banners in application/xhtml+xml documents

how to do it
templates.pl:
replace &thread= with &thread=
replace text/html with application/xhtml+xml
replace document.threadform with document.forms.threadform

kareha.pl:
replace text/html with application/xhtml+xml

kareha.js:
replace document.threadform with document.forms.threadform
replace nodeName=="A" with nodeName.toLowerCase()=="a"

.htaccess:
add AddType application/xhtml+xml html