# Autoriser ce genre de directives dans le vhost:
# <Directory /var/www/site>
#   AllowOverride FileInfo
# </Directory>

AddHandler application/x-httpd-php .xsl
# ou, selon ton environnement :
#AddType application/x-httpd-php .xsl

AddHandler application/x-httpd-php .xml
# ou, selon ton environnement :
#AddType application/x-httpd-php .xml

<IfModule mod_mime.c>
    # XML
    AddType application/xml .xml
    # XSLT / XSL
    AddType application/xslt+xml .xsl .xslt
</IfModule>