The typical mechanism for sharing notebooks is to provide your notebook on a website. A website runs on a server or on allocated machine space. The server takes care of all the bookkeeping involved in running a website, such as keeping track of multiple users and logging people on and off.

In order for the notebook to be of use, though, the website must have notebook logic installed. A typical website knows how to deliver content as HTML given some source files. The most basic form is pure HTML, where every page you access on the website corresponds exactly to one HTML file on the web server. Other languages could be used to develop the website (such as Java or PHP), so then the server needs to know how to access the HTML it needs from those source files. In our context, the server needs to know how to access your notebook in order to deliver HTML to users.

Even when notebooks are just running on your local machine, they are running in a browser that is accessing your local...