RewriteEngine On
#Redirect http://diffen.com to http://www.diffen.com
RewriteCond %{HTTP_HOST} ^diffen.com
RewriteRule ^(.*)$ http://www.diffen.com/$1 [r=301,L]
RedirectMatch ^/$ http://www.diffen.com/difference
RewriteCond %{REQUEST_URI} ^/difference$
RewriteRule ^(.*) /difference/index.php?title=Main_Page [L]

RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d

RewriteCond %{THE_REQUEST} ^[A-Z]+\ /difference/([^?\ ]+)
RewriteRule ^difference/(.+)$ /difference/index.php?title=%1 [NE,L,QSA] 

IndexIgnore */*