Use The Vi Text Editor In Your Web Browser
If you keep hearing about vi ("vee eye") from your Linux friends but never had a chance to experience this powerful text editor yourself, here’s something for you.
A web hosting company called "Internet Connection" has written a clone of Vi in Javascript that lets you run Vi inside any web browser. You don’t have to install any software.
This online vi-clone is known as jsvi and it supports almost all the regular vi keys and substitution commands. There’s also an inbuilt spell checker plus you can copy-paste text from the clipboard.
The other standard option is VIM - a desktop based Vi client that’s more advanced than the main Unix version and is available for all platforms.

If it moves along this way i guess day wont be far that you would be able to use an Operating System over the web.
I wonder if we can have a firefox online ?
I don’t want VI, I want emacs!!!
#1 = There are many online OS already - http://www.google.com/search?q=Online+OS