RewriteEngine On
RewriteCond %{HTTP:HOST} http://mysite.com/
RewriteCond %{HTTP:Accept-Language} ^en [NC] RewriteRule ^$ http://mysite.com/en/ [L,R=301]
RewriteCond %{HTTP:Accept-Language} ^de [NC] RewriteRule ^$ http://mysite.com/de/ [L,R=301]
RewriteCond %{HTTP:Accept-Language} ^nl [NC] RewriteRule ^$ http://mysite.com/nl/ [L,R=301]
RewriteCond %{HTTP:Accept-Language} ^fr [NC] RewriteRule ^$ http://mysite.com/fr/ [L,R=301]
RewriteCond %{HTTP:Accept-Language} ^es [NC] RewriteRule ^$ http://mysite.com/es/ [L,R=301]
RewriteCond %{REQUEST_FILENAME} !-d RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-l
RewriteRule ^(en|de|nl|fr|es)$ index.php?lang=$1 [L,QSA]