EnforceSSL is a Rack middleware app that enforces that users visit specific paths via HTTPS. If a sensitive path is requested over plain-text HTTP, a 307 Redirect will be issued leading to the HTTPS version of the Requested URI.

BanHammer is a Rack middleware app that restricts access to your server using a black-list of IPv4/IPv6 addresses and ranges.

RefererControl is a Rack middleware app which restricts access to paths based on the Referer header. Using RefererControl you can make sure users follow the intended flow of a website. If a controlled path is visited with an unacceptable Referer URI, then a simple 307 Redirect response is returned.

RefererControl should also make Cross Site Request Forgery (CSRF) a little more difficult to exploit; but not impossible using JavaScript.

The LieServer is a simple Rack middleware app which allows one to spoof the Server header in responses for every request, requests to certain sub-directories or paths which match a regular expression.