Normalize URLs makes WordPress to play more nicely regarding URLs in HTTP Requests.
Wp Private Access adds an http authentication dialog using WordPress users database
Domain Theme allows you to specify more then one domain name with your WordPress installation and assign individual themes to each one.
Check to see if SSL is used. This will update any template functions which require SSL to be used.
Checks to see if the author name in your comments contains "HTTP:" to help filter out spam.