Re: Original Sin
Deep in the mists of time, there were a number of websites that would complain to Firefox and Netscape that their site 'only works with Internet Explorer' <some version>.
Changing the UA string (pretty simple to do in Firefox) got rid of the complaint and in the vast majority of cases the site worked just fine.
One company I worked for from 1998 had some developers in California (I was sitting in my office in Princeton NJ running Netscape on an SGI Indy) where an internal set of pages written by said developers gave me an error that 'your browser does not support frames'. Quite amusing really as those were invented at Netscape IIRC.