What a fun and what a joke as well.
Who said the site doesn't require internet? Must be kidding!
And believe me, no complex algorithm. There is no such algorith in developing this kind of fun.
How it is done technically?
Switch off the net connection and type
As usual, the message shows "no internet connection"
Now switch on internet
type the url
It will say, to explore the web you need to switch off net. Thats the funny and tricky part.
The site is a flash based site and a code is writen which fires in time interval - which checks internet.
If net connection found - shows funny message (internet required) and swf stops playing.
If no net connection, swf runs.
Its a good fun.
Technically speaking, if you are accessing site that is not local - without net you cannot. What you can see is a cached version.