Interchange catalog at root URL. Prevents Interchange from having to handle all 404 requests, unless the request does not have an extension, or is a known file type that IC serves.

httpd.conf

ScriptAlias /cgi-bin/ /home/mysite/cgi-bin/
RewriteEngine On

RewriteRule ^/index(\.html?)?$  /  [R=301]
RewriteRule ^/?$  /cgi-bin/mysite/index  [L,NS,PT]

RewriteCond  %{DOCUMENT_ROOT}%{REQUEST_FILENAME} -f
RewriteRule  ^  -  [L,NS]

RewriteCond  %{REQUEST_FILENAME}  \.
RewriteCond  %{REQUEST_FILENAME}  !\.(?:html|txt|xml|pdf|iif)$
RewriteRule  ^  -  [L,NS]

RewriteCond  %{REQUEST_FILENAME}  !^/cgi-bin/.+
RewriteRule  ^(.+)$  /cgi-bin/mysite$1  [L,NS,PT]