RewriteEngine on
RewriteBase /widget4k

RewriteCond %{THE_REQUEST} "^\S* .*?\.(php|cgi)[? ].*$"
RewriteRule .* - [L,F]

# main conversions
RewriteRule ^(rules)(/|\.htm)?$ $1.php [L]
RewriteRule ^(upload)(\.xml)?$ $1.php [L]

RewriteRule ^gallery(/|\.htm)?$ gallery.cgi [L]
RewriteRule ^gallery\.xml$ gallery.cgi?xml=1 [L]
RewriteRule ^gallery/(page|widget)(\d+)(/|\.htm)?$ gallery.cgi?$1=$2 [L]
RewriteRule ^gallery/(page|widget)(\d+)\.xml$ gallery.cgi?$1=$2&xml=1 [L]