This NginX module strips the page of all newlines ('\n', '\r') and extra white-space ('\t' and extra ' ') before serving it. It follow the 'reddit' method of stripping out space everywhere except in areas marked between HTML comments <!--SC_OFF--> and <!--SC_ON-->
If you wish to learn about writting nginx-modules, Evan Miller has written an excellent guide which can be found here: http://www.evanmiller.org/nginx-modules-guide.html